Year 4 Tenths, Hundredths and Money: worked examples and questions with answers
By the end of this chapter you will be able to
- Write tenths and hundredths as fractions and as decimals, and know what each digit is worth
- Use place-value charts, hundred squares and number lines to show decimals with up to two decimal places
- Write 1/2, 1/4 and 3/4 as the decimals 0.5, 0.25 and 0.75
- Count up and down in tenths and hundredths, including across a whole number
- Divide one- and two-digit numbers by 10 and 100 by moving the digits to the right
- Compare and order decimals, and round a decimal with one decimal place to the nearest whole number
- Write amounts of money in pounds and pence, change between £ and p, and compare money
- Add, subtract, multiply and share money, work out change, and solve simple measure problems with decimals
You should already know
- Tenths and hundredths as fractions (Chapter 5)
- Place value of whole numbers and rounding to the nearest 10 (Chapter 1)
- Adding and subtracting with columns (Chapter 2)
- Times tables and multiplying and dividing by 10 and 100 (Chapters 3 and 4)
Where this leads
- Converting units of length, mass and capacity (Chapter 7)
- Decimals with three places and percentages in Year 5
- Adding and subtracting decimals with more digits in Year 5
- Multiplying and dividing decimals in Year 6
National Curriculum for England, Key Stage 2 mathematics, Year 4. Content: Recognise that hundredths arise when dividing an object by 100 and dividing tenths by ten, Count up and down in hundredths; recognise and write decimal equivalents of any number of tenths or hundredths, Recognise and write decimal equivalents to 1/4, 1/2 and 3/4, Find the effect of dividing a one- or two-digit number by 10 and 100, identifying the value of the digits in the answer as ones, tenths and hundredths, Round decimals with one decimal place to the nearest whole number, Compare numbers with the same number of decimal places up to two decimal places, Solve simple measure and money problems involving fractions and decimals to two decimal places, Estimate, compare and calculate money in pounds and pence.
- 6.1 Tenths as decimals: Worksheet (PDF) · Answers (PDF) · lesson page
- 6.2 Hundredths and place value: Worksheet (PDF) · Answers (PDF) · lesson page
- 6.3 Halves, quarters and three quarters: Worksheet (PDF) · Answers (PDF) · lesson page
- 6.4 Dividing by 10 and 100: Worksheet (PDF) · Answers (PDF) · lesson page
- 6.5 Comparing, ordering and rounding decimals: Worksheet (PDF) · Answers (PDF) · lesson page
- 6.6 Money: pounds and pence: Worksheet (PDF) · Answers (PDF) · lesson page
- 6.7 Adding, subtracting and money problems: Worksheet (PDF) · Answers (PDF) · lesson page
- Check-up and SATs-style questions: Worksheet (PDF) · Answers (PDF) · lesson page
Exercise P Do you remember?
Non-calculatorKey words. The denominator (bottom number) is how many equal parts. The numerator (top number) is how many parts we have.
Method. Tenths are made by cutting a whole into 10 equal parts. Count the shaded parts for the top number.
- Count the equal parts. The whole is cut into 10 equal parts. Each part is one tenth.There are 10 parts, so the bottom number is 10.
- Count the shaded parts. This is the top number.3 parts are shaded, so the top number is 3.
- Write the fraction.
(say “three tenths”)3 10
Check. 3 shaded and 7 white make 10 parts. ✓
Watch out. The bottom number is the number of parts in the whole (10), not the number shaded.
Method. Dividing by 10 makes a number 10 times smaller. Think about how many tens there are.
- Think about tens. 560 is 5 hundreds and 6 tens, which is 56 tens.560 ÷ 10 = 56
- Check with a multiplication. Multiplying by 10 should take us back.56 × 10 = 560
Check. 56 × 10 = 560. ✓
Watch out. Each digit moves one place to the right when you divide by 10.
Method. 100 pence make 1 pound, so multiply the pounds by 100.
- Remember: £1 = 100p. Pence are small amounts of money.£1 = 100p
- Multiply by 2. There are 2 pounds.2 × 100p = 200p
Check. 200p ÷ 100 = £2. ✓
Watch out. Always write the unit (p) in the answer.
Key words. To round a number is to change it to a nearby number that is easier to use. ≈ means “is about equal to”.
Method. Look at the digit to the right of the one you are rounding to. If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two multiples of 10 that 47 is between. Rounding to the nearest 10 means choosing the closest multiple of 10.40 < 47 < 50
- Look at the ones digit (the digit just to the right of the tens digit). This digit tells us if we are past halfway.The ones digit is 7.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down.7 is 5 or more, so round up.
- Write the rounded number. Digits to the right of the tens column become zeros.47 ≈ 50 (to the nearest 10)
Check. Distances: 47 − 40 = 7 and 50 − 47 = 3. 50 is the nearer one. ✓
Watch out. Only the digit just to the right decides. Do not look at digits further along.
Key words. < means “less than” and > means “greater than”. The wide end of the sign faces the bigger number.
Method. Compare the digits from the left, one column at a time. The first column that is different tells you which number is bigger.
- Write both numbers in a place-value table. Lining up the columns lets us compare digit by digit.
Th H T O 4,350 4 3 5 0 4,305 4 3 0 5 - Compare the digits from the left. The first column where they are different decides which number is bigger.thousands: 4 and 4 are the same, so look at the next column.
hundreds: 3 and 3 are the same, so look at the next column.
tens: 5 and 0 are different. 5 > 0, so 4,350 is bigger. - Write the correct symbol. < means “is less than”, > means “is greater than”, = means “is equal to”.4,350 > 4,305
Check. Picture a number line: 4,305 is to the left of 4,350. ✓
Watch out. Start at the LEFT (the biggest column). Do not start with the ones.
Tenths as decimals
Printable: Worksheet (PDF) · Answers (PDF) · Open this lesson on its own page
In Chapter 5 you cut a whole into 10 equal parts. Each part is one tenth, written 1/10. There is another way to write a tenth. We can write it as a decimal: 0.1. The dot is called the decimal point.
The decimal point separates the whole numbers from the parts of a whole. Digits to the left of the point are whole numbers (ones, tens...). The first digit to the right of the point is the tenths digit. So 0.3 means 0 ones and 3 tenths.
On a number line. Between 0 and 1 there are 10 equal gaps. Each gap is one tenth, 0.1.
More than one. We can have whole ones and tenths. 2 and 4 tenths is the mixed number 2 4/10, and as a decimal it is 2.4. The 2 is in the ones column and the 4 is in the tenths column.
Counting in tenths. Count on 0.1 each time: 0.7, 0.8, 0.9, 1.0, 1.1, 1.2. Ten tenths make one whole, so 0.9 + 0.1 = 1.0. The number 1.0 is the same as 1. Counting back works the same way: 1.2, 1.1, 1.0, 0.9, 0.8.
Dividing by 10. Dividing 1 whole by 10 gives one tenth: 1 ÷ 10 = 0.1. And 3 ÷ 10 = 0.3. You will see more about this in Section 6.4.
Key words. A decimal is a number with a decimal point. Tenths are the first column after the point.
Key ideas
- A tenth is 1 of 10 equal parts: 1/10 = 0.1.
- The decimal point separates whole numbers (left) from parts of a whole (right).
- The first digit after the point is the tenths digit: 0.7 is 7 tenths = 7/10.
- 10 tenths make 1 whole: 0.9 + 0.1 = 1.0.
- A mixed number with tenths is a decimal: 2 4/10 = 2.4.
- Write a 0 before the point when there are no whole ones: 0.7 (not .7).
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the tenths that are shaded. Tenths are the first column after the decimal point.
- Count the equal parts in the whole. The whole is cut into 10 equal parts. Each part is one tenth.There are 10 parts, so the bottom number is 10.
- Count the shaded parts. This gives the top number.7 parts are shaded, so the fraction is
.7 10 - Write it as a decimal. Tenths go in the first column after the decimal point.
ones tenths 0.7 0 . 7
0 ones and 7 tenths = 0.7
Check. Go back to a fraction: 0.7 has 7 in the tenths column, so it is
Watch out. Write the 0 ones before the decimal point: 0.7, not .7.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 10 means tenths. Tenths go in the first column after the decimal point.
is 4 tenths.4 10 - Look at the picture.
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths 0.4 0 . 4 - Write the decimal.
= 0.44 10
Check. Go back to a fraction: 0.4 =
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 10 means tenths. Tenths go in the first column after the decimal point.2310 is 2 ones and 3 tenths.
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths 2.3 2 . 3 - Write the decimal. 2310 = 2.3
Check. Go back to a fraction: 2.3 = 2310. ✓
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.9 has 1 digit after the point, so the bottom number is 10.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 9, which is 9.
- Write the fraction. 0.9 =
(9 tenths)9 10
Check. Go back:
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Work out what one gap is worth. Then count on from the left end.
- Find the two numbers at the ends and count the gaps. All the gaps on a number line are the same size.The line goes from 1 to 2 in 10 equal gaps.
- Work out what one gap is worth. Share the distance between the ends equally.1 ÷ 10 = 0.1
- Count the gaps from the left end to the point. Count the gaps, not the tick marks.The point is 4 gaps after 1.
- Work out the number. Start at the left end and add the gaps.1 + 4 × 0.1 = 1 + 0.4 = 1.4
Check. Count back from 2: 6 gaps back is 2 − 0.6 = 1.4. ✓
Watch out. Do not just read the nearest number on the line. Count the small gaps to find the exact value.
0.6, 0.7, ?, 0.9, ?, 1.1
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Find the jump. Then count on in tenths, one jump at a time.
- Find the jump between two numbers you know. The numbers go up by the same amount each time.0.6 to 0.7: the jump is 0.1 (1 tenth)
- Count on in tenths. 10 tenths make 1 whole, so after 0.9 comes 1.0.0.6, 0.7, 0.8, 0.9, 1.0, 1.1
- Write the missing numbers. 0.8, 1.0
Check. Count on again from the first number. The jump is always 0.1. ✓
Watch out. Keep one decimal place each time: write 1.0 (not 1) in a tenths sequence.
2.2, 2.1, ?, 1.9, ?, 1.7
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Find the jump. Then count back in tenths, one jump at a time.
- Find the jump between two numbers you know. The numbers go down by the same amount each time.2.2 to 2.1: the jump is 0.1 (1 tenth)
- Count back in tenths. Going back, 1.0 is the same as 10 tenths, so before 1.0 comes 0.9.2.2, 2.1, 2.0, 1.9, 1.8, 1.7
- Write the missing numbers. 2.0, 1.8
Check. Count back again from the first number. The jump is always 0.1. ✓
Watch out. Keep one decimal place each time: write 1.0 (not 1) in a tenths sequence.
Watch out
3/10 is 0.3, not 3.10 and not 0.10. The digit after the point is the number of tenths. Also, do not forget the whole number when you count: after 0.9 comes 1.0, then 1.1.Exercise 6A Tenths as decimals
Non-calculatorKey words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the tenths that are shaded. Tenths are the first column after the decimal point.
- Count the equal parts in the whole. The whole is cut into 10 equal parts. Each part is one tenth.There are 10 parts, so the bottom number is 10.
- Count the shaded parts. This gives the top number.3 parts are shaded, so the fraction is
.3 10 - Write it as a decimal. Tenths go in the first column after the decimal point.
ones tenths 0.3 0 . 3
0 ones and 3 tenths = 0.3
Check. Go back to a fraction: 0.3 has 3 in the tenths column, so it is
Watch out. Write the 0 ones before the decimal point: 0.7, not .7.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the tenths that are shaded. Tenths are the first column after the decimal point.
- Count the equal parts in the whole. The whole is cut into 10 equal parts. Each part is one tenth.There are 10 parts, so the bottom number is 10.
- Count the shaded parts. This gives the top number.8 parts are shaded, so the fraction is
.8 10 - Write it as a decimal. Tenths go in the first column after the decimal point.
ones tenths 0.8 0 . 8
0 ones and 8 tenths = 0.8
Check. Go back to a fraction: 0.8 has 8 in the tenths column, so it is
Watch out. Write the 0 ones before the decimal point: 0.7, not .7.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the tenths that are shaded. Tenths are the first column after the decimal point.
- Count the equal parts in the whole. The whole is cut into 10 equal parts. Each part is one tenth.There are 10 parts, so the bottom number is 10.
- Count the shaded parts. This gives the top number.5 parts are shaded, so the fraction is
.5 10 - Write it as a decimal. Tenths go in the first column after the decimal point.
ones tenths 0.5 0 . 5
0 ones and 5 tenths = 0.5
Check. Go back to a fraction: 0.5 has 5 in the tenths column, so it is
Watch out. Write the 0 ones before the decimal point: 0.7, not .7.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 10 means tenths. Tenths go in the first column after the decimal point.
is 2 tenths.2 10 - Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths 0.2 0 . 2 - Write the decimal.
= 0.22 10
Check. Go back to a fraction: 0.2 =
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 10 means tenths. Tenths go in the first column after the decimal point.
is 5 tenths.5 10 - Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths 0.5 0 . 5 - Write the decimal.
= 0.55 10
Check. Go back to a fraction: 0.5 =
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 10 means tenths. Tenths go in the first column after the decimal point.
is 9 tenths.9 10 - Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths 0.9 0 . 9 - Write the decimal.
= 0.99 10
Check. Go back to a fraction: 0.9 =
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 10 means tenths. Tenths go in the first column after the decimal point.
is 1 tenth.1 10 - Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths 0.1 0 . 1 - Write the decimal.
= 0.11 10
Check. Go back to a fraction: 0.1 =
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 10 means tenths. Tenths go in the first column after the decimal point.
is 7 tenths.7 10 - Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths 0.7 0 . 7 - Write the decimal.
= 0.77 10
Check. Go back to a fraction: 0.7 =
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 10 means tenths. Tenths go in the first column after the decimal point.
is 4 tenths.4 10 - Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths 0.4 0 . 4 - Write the decimal.
= 0.44 10
Check. Go back to a fraction: 0.4 =
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.3 has 1 digit after the point, so the bottom number is 10.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 3, which is 3.
- Write the fraction. 0.3 =
(3 tenths)3 10
Check. Go back:
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.7 has 1 digit after the point, so the bottom number is 10.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 7, which is 7.
- Write the fraction. 0.7 =
(7 tenths)7 10
Check. Go back:
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.1 has 1 digit after the point, so the bottom number is 10.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 1, which is 1.
- Write the fraction. 0.1 =
(1 tenth)1 10
Check. Go back:
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.9 has 1 digit after the point, so the bottom number is 10.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 9, which is 9.
- Write the fraction. 0.9 =
(9 tenths)9 10
Check. Go back:
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.6 has 1 digit after the point, so the bottom number is 10.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 6, which is 6.
- Write the fraction. 0.6 =
(6 tenths)6 10
Check. Go back:
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.4 has 1 digit after the point, so the bottom number is 10.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 4, which is 4.
- Write the fraction. 0.4 =
(4 tenths)4 10
Check. Go back:
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 10 means tenths. Tenths go in the first column after the decimal point.1410 is 1 one and 4 tenths.
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths 1.4 1 . 4 - Write the decimal. 1410 = 1.4
Check. Go back to a fraction: 1.4 = 1410. ✓
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 10 means tenths. Tenths go in the first column after the decimal point.3710 is 3 ones and 7 tenths.
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths 3.7 3 . 7 - Write the decimal. 3710 = 3.7
Check. Go back to a fraction: 3.7 = 3710. ✓
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 10 means tenths. Tenths go in the first column after the decimal point.2110 is 2 ones and 1 tenth.
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths 2.1 2 . 1 - Write the decimal. 2110 = 2.1
Check. Go back to a fraction: 2.1 = 2110. ✓
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 10 means tenths. Tenths go in the first column after the decimal point.5910 is 5 ones and 9 tenths.
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths 5.9 5 . 9 - Write the decimal. 5910 = 5.9
Check. Go back to a fraction: 5.9 = 5910. ✓
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.1.5 has 1 digit after the point, so the bottom number is 10.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 5, which is 5.
- Write the whole number in front. The 1 before the point stays as a whole number.1 and
5 10 - Write the fraction. 1.5 = 1510 (5 tenths)
Check. Go back: 1510 written as a decimal is 1.5. ✓
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.3.2 has 1 digit after the point, so the bottom number is 10.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 2, which is 2.
- Write the whole number in front. The 3 before the point stays as a whole number.3 and
2 10 - Write the fraction. 3.2 = 3210 (2 tenths)
Check. Go back: 3210 written as a decimal is 3.2. ✓
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.4.8 has 1 digit after the point, so the bottom number is 10.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 8, which is 8.
- Write the whole number in front. The 4 before the point stays as a whole number.4 and
8 10 - Write the fraction. 4.8 = 4810 (8 tenths)
Check. Go back: 4810 written as a decimal is 4.8. ✓
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.2.7 has 1 digit after the point, so the bottom number is 10.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 7, which is 7.
- Write the whole number in front. The 2 before the point stays as a whole number.2 and
7 10 - Write the fraction. 2.7 = 2710 (7 tenths)
Check. Go back: 2710 written as a decimal is 2.7. ✓
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Work out what one gap is worth. Then count on from the left end.
- Find the two numbers at the ends and count the gaps. All the gaps on a number line are the same size.The line goes from 0 to 1 in 10 equal gaps.
- Work out what one gap is worth. Share the distance between the ends equally.1 ÷ 10 = 0.1
- Count the gaps from the left end to the point. Count the gaps, not the tick marks.The point is 2 gaps after 0.
- Work out the number. Start at the left end and add the gaps.0 + 2 × 0.1 = 0 + 0.2 = 0.2
Check. Count back from 1: 8 gaps back is 1 − 0.8 = 0.2. ✓
Watch out. Do not just read the nearest number on the line. Count the small gaps to find the exact value.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Work out what one gap is worth. Then count on from the left end.
- Find the two numbers at the ends and count the gaps. All the gaps on a number line are the same size.The line goes from 0 to 1 in 10 equal gaps.
- Work out what one gap is worth. Share the distance between the ends equally.1 ÷ 10 = 0.1
- Count the gaps from the left end to the point. Count the gaps, not the tick marks.The point is 6 gaps after 0.
- Work out the number. Start at the left end and add the gaps.0 + 6 × 0.1 = 0 + 0.6 = 0.6
Check. Count back from 1: 4 gaps back is 1 − 0.4 = 0.6. ✓
Watch out. Do not just read the nearest number on the line. Count the small gaps to find the exact value.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Work out what one gap is worth. Then count on from the left end.
- Find the two numbers at the ends and count the gaps. All the gaps on a number line are the same size.The line goes from 0 to 1 in 10 equal gaps.
- Work out what one gap is worth. Share the distance between the ends equally.1 ÷ 10 = 0.1
- Count the gaps from the left end to the point. Count the gaps, not the tick marks.The point is 9 gaps after 0.
- Work out the number. Start at the left end and add the gaps.0 + 9 × 0.1 = 0 + 0.9 = 0.9
Check. Count back from 1: 1 gap back is 1 − 0.1 = 0.9. ✓
Watch out. Do not just read the nearest number on the line. Count the small gaps to find the exact value.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Find the jump. Then count on in tenths, one jump at a time.
- Find the jump between two numbers you know. The numbers go up by the same amount each time.0.2 to 0.3: the jump is 0.1 (1 tenth)
- Count on in tenths. 10 tenths make 1 whole, so after 0.9 comes 1.0.0.2, 0.3, 0.4, 0.5, 0.6, 0.7
- Write the missing numbers. 0.4, 0.6
Check. Count on again from the first number. The jump is always 0.1. ✓
Watch out. Keep one decimal place each time: write 1.0 (not 1) in a tenths sequence.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Find the jump. Then count on in tenths, one jump at a time.
- Find the jump between two numbers you know. The numbers go up by the same amount each time.0.9 to 1.0: the jump is 0.1 (1 tenth)
- Count on in tenths. 10 tenths make 1 whole, so after 0.9 comes 1.0.0.7, 0.8, 0.9, 1.0, 1.1, 1.2
- Write the missing numbers. 0.8, 1.1
Check. Count on again from the first number. The jump is always 0.1. ✓
Watch out. Keep one decimal place each time: write 1.0 (not 1) in a tenths sequence.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Find the jump. Then count on in tenths, one jump at a time.
- Find the jump between two numbers you know. The numbers go up by the same amount each time.1.4 to 1.5: the jump is 0.1 (1 tenth)
- Count on in tenths. 10 tenths make 1 whole, so after 0.9 comes 1.0.1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0
- Write the missing numbers. 1.7, 1.9
Check. Count on again from the first number. The jump is always 0.1. ✓
Watch out. Keep one decimal place each time: write 1.0 (not 1) in a tenths sequence.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Find the jump. Then count back in tenths, one jump at a time.
- Find the jump between two numbers you know. The numbers go down by the same amount each time.0.9 to 0.8: the jump is 0.1 (1 tenth)
- Count back in tenths. Going back, 1.0 is the same as 10 tenths, so before 1.0 comes 0.9.0.9, 0.8, 0.7, 0.6, 0.5, 0.4
- Write the missing numbers. 0.7, 0.5
Check. Count back again from the first number. The jump is always 0.1. ✓
Watch out. Keep one decimal place each time: write 1.0 (not 1) in a tenths sequence.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Find the jump. Then count back in tenths, one jump at a time.
- Find the jump between two numbers you know. The numbers go down by the same amount each time.0.9 to 0.8: the jump is 0.1 (1 tenth)
- Count back in tenths. Going back, 1.0 is the same as 10 tenths, so before 1.0 comes 0.9.1.3, 1.2, 1.1, 1.0, 0.9, 0.8
- Write the missing numbers. 1.2, 1.0
Check. Count back again from the first number. The jump is always 0.1. ✓
Watch out. Keep one decimal place each time: write 1.0 (not 1) in a tenths sequence.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Find the jump. Then count back in tenths, one jump at a time.
- Find the jump between two numbers you know. The numbers go down by the same amount each time.2.1 to 2.0: the jump is 0.1 (1 tenth)
- Count back in tenths. Going back, 1.0 is the same as 10 tenths, so before 1.0 comes 0.9.2.1, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5
- Write the missing numbers. 1.9, 1.6
Check. Count back again from the first number. The jump is always 0.1. ✓
Watch out. Keep one decimal place each time: write 1.0 (not 1) in a tenths sequence.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Change each column into tenths, then add them.
- Split the number into its columns. Each digit is worth a different amount.0.6 = 0 ones and 6 tenths
- Change each part into tenths. 1 whole = 10 tenths.6 tenths
6 tenths - Write the answer. 6 tenths
Check. 6 tenths written as a decimal is 0.6. ✓
Watch out. Do not forget the whole ones: each one is worth 10 tenths.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Change each column into tenths, then add them.
- Split the number into its columns. Each digit is worth a different amount.1.3 = 1 one and 3 tenths
- Change each part into tenths. 1 whole = 10 tenths.1 whole one = 1 × 10 = 10 tenths
3 tenths
10 + 3 = 13 tenths - Write the answer. 13 tenths
Check. 13 tenths written as a decimal is 1.3. ✓
Watch out. Do not forget the whole ones: each one is worth 10 tenths.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Change each column into tenths, then add them.
- Split the number into its columns. Each digit is worth a different amount.2.5 = 2 ones and 5 tenths
- Change each part into tenths. 1 whole = 10 tenths.2 whole ones = 2 × 10 = 20 tenths
5 tenths
20 + 5 = 25 tenths - Write the answer. 25 tenths
Check. 25 tenths written as a decimal is 2.5. ✓
Watch out. Do not forget the whole ones: each one is worth 10 tenths.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Change each column into tenths, then add them.
- Split the number into its columns. Each digit is worth a different amount.4.1 = 4 ones and 1 tenth
- Change each part into tenths. 1 whole = 10 tenths.4 whole ones = 4 × 10 = 40 tenths
1 tenth
40 + 1 = 41 tenths - Write the answer. 41 tenths
Check. 41 tenths written as a decimal is 4.1. ✓
Watch out. Do not forget the whole ones: each one is worth 10 tenths.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. A tenth of a metre is 0.1 m. Count how many tenths she uses.
- Find the size of one piece. The ribbon is cut into 10 equal pieces, so each piece is one tenth of a metre.1 piece =
m = 0.1 m1 10 - Count the pieces she uses. She uses 7 pieces.7 pieces = 7 tenths =
m7 10 - Write it as a decimal. 7 tenths is 0 ones and 7 tenths.
m = 0.7 m7 10
Check. 10 pieces make 1 m. She uses 7 and has 3 left: 0.7 + 0.3 = 1.0. ✓
Watch out. Each piece is 0.1 m, not 1 m. Seven pieces is 0.7 m.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Each lap is one tenth of the race. Count the laps Tom has run.
- Find what one lap is worth. The race has 10 laps, so each lap is one tenth.1 lap =
= 0.11 10 - Count the laps run. 6 laps is 6 tenths.
= 0.66 10
Check. 0.6 has 6 in the tenths column. ✓
Watch out. The bottom number is all 10 laps, not the 6 laps Tom has run.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. The laps left are the laps not yet run. Find how many tenths are left.
- Find the laps left. Take the laps run away from the 10 laps in the race.10 − 6 = 4 laps
- Write it as a decimal. 4 laps is 4 tenths.
= 0.44 10
Check. 0.6 + 0.4 = 1.0, the whole race. ✓
Watch out. 0.6 and 0.4 make 1 whole.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Write each one as a decimal. Look for the one that is worth a different amount.
- Write each as a decimal. 3/10 means 3 tenths. “Three tenths” is the same.
= 0.3 three tenths = 0.3 0.3 = 0.3 0.03 = 3 hundredths3 10 - Find the odd one out. 0.03 has a 0 in the tenths column, so it is much smaller.0.03
Check. 0.03 is 3 hundredths, which is not the same as 3 tenths. ✓
Watch out. The 0 after the point matters: 0.03 is not 0.3.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Say each number in words and check it against the fraction.
- Look at what Leo wrote. Leo wrote
= 3.10.3 10 3.10 means 3 ones and 10 hundredths (which is 3 and 1 tenth), not 3 tenths. - Find the mistake. Leo wrote the 10 from the bottom of the fraction after the point. The bottom number says that we are counting tenths.
is only 3 tenths.3 10 - Write it correctly. Put the 3 in the tenths column. There are 0 whole ones.
= 0.33 10
Check. 0.3 is less than 1 and 3.10 is more than 3, so they cannot be equal. ✓
Watch out. Only the top number goes in the tenths column.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. The ones digit is 2 because the number is between 2 and 3. The tenths digit is double the ones digit.
- Find the ones digit. A number between 2 and 3 has 2 ones.ones digit = 2
- Find the tenths digit. It is double the ones digit.2 × 2 = 4
- Write the number. 2 ones and 4 tenths.2.4
Check. 2.4 is between 2 and 3, and the tenths digit 4 is double the ones digit 2. ✓
Watch out. Check every clue in the puzzle at the end.
Hundredths and place value
Printable: Worksheet (PDF) · Answers (PDF) · Open this lesson on its own page
Cut each tenth into 10 equal parts. Now the whole is cut into 10 × 10 = 100 equal parts. Each part is one hundredth, written 1/100 or 0.01. So dividing a tenth by 10 makes a hundredth: 0.1 ÷ 10 = 0.01.
A hundred square shows hundredths. Each small square is 0.01. Each row of 10 squares is one tenth, 0.1. If 37 squares are shaded, then 3 rows (3 tenths) and 7 more squares (7 hundredths) are shaded. That is 37/100 = 0.37.
Two decimal places. The second digit after the point is the hundredths digit. In 0.37 there are 0 ones, 3 tenths and 7 hundredths.
A zero keeps a place. 0.05 is not the same as 0.5. In 0.05 there are no tenths, so the tenths column holds a 0. Look at the squares.
0.05 (5 hundredths)
0.5 (5 tenths)
The value of each digit. In 3.45 the 3 is worth 3 ones (3), the 4 is worth 4 tenths (0.4) and the 5 is worth 5 hundredths (0.05). We can split a number up like this: 3.45 = 3 + 0.4 + 0.05.
On a number line. Zoom in on the line from 0.3 to 0.4. It is cut into 10 gaps. Each gap is a hundredth, 0.01.
Counting in hundredths. 0.07, 0.08, 0.09, then 0.10 (that is 10 hundredths = 1 tenth), 0.11, 0.12. And past a whole: 0.98, 0.99, 1.00, 1.01. Counting back: 0.12, 0.11, 0.10, 0.09.
Key words. A hundredth is one of 100 equal parts of a whole. It is the second column after the decimal point.
Key ideas
- A hundredth is 1 of 100 equal parts: 1/100 = 0.01.
- 10 hundredths make 1 tenth: 0.10 = 0.1.
- The first digit after the point is tenths and the second digit is hundredths.
- 37 hundredths = 37/100 = 0.37 = 3 tenths and 7 hundredths.
- Use a 0 to hold a place: 5 hundredths is 0.05 (not 0.5).
- Split a decimal by the value of its digits: 3.45 = 3 + 0.4 + 0.05.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. A hundred square has 100 small squares. Each is one hundredth. Count the shaded squares, then write the decimal.
- Count the small squares in the whole. There are 10 rows of 10 small squares. Each small square is one hundredth.10 × 10 = 100 squares
- Count the shaded squares. Count the full rows first (10 squares each), then the extra squares.3 full rows = 30 squares
30 + 7 = 37 squares - Write the fraction. The top number is the shaded squares.
37 100 - Write it as a decimal. Tenths are the first column after the point and hundredths are the second column.
ones tenths hundredths 0.37 0 . 3 7
37 hundredths = 0 ones, 3 tenths and 7 hundredths, so 0.37
Check. Go back: 0.37 is
Watch out. Each row of 10 squares is one tenth (0.1). Count in tens to be quick.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 100 means hundredths. Tenths go in the first column after the point and hundredths in the second column.
is 7 hundredths.7 100 - Notice there are no tenths. 7 hundredths is less than 1 tenth (1 tenth = 10 hundredths). The tenths column must hold a 0.0 tenths and 7 hundredths
- Look at the picture.
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths hundredths 0.07 0 . 0 7 - Write the decimal.
= 0.077 100
Check. Go back to a fraction: 0.07 =
Watch out. 7 hundredths is 0.07, not 0.7. The 0 in the tenths column keeps the 7 in the hundredths column.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.63 has 2 digits after the point, so the bottom number is 100.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 63, which is 63.
- Write the fraction. 0.63 =
(63 hundredths)63 100
Check. Go back:
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Put each digit in its column of the place-value table. Write a 0 in any empty column. Then write the number with the point after the ones.
- Draw a place-value table. The columns are ones, then tenths, then hundredths.
ones tenths hundredths 8.04 8 . 0 4 - Write each digit in its column. A column with none in it still needs a 0 so the other digits stay in the right place.8 ones, 0 tenths and 4 hundredths
- Write the number. Put the decimal point between the ones and the tenths.8.04
Check. Read it back: 8.04 is 8 ones, 0 tenths and 4 hundredths. ✓
Watch out. Do not leave out a 0. Two ones, no tenths and 7 hundredths is 2.07, not 2.7.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Split the number into the value of each digit and write them as an addition.
- Write the number in a place-value table.
ones tenths hundredths 5.82 5 . 8 2 - Work out the value of each digit. A zero digit is worth nothing, so we can leave it out.5 ones = 5
8 tenths = 0.8
2 hundredths = 0.02 - Write the parts as an addition. 5.82 = 5 + 0.8 + 0.02
Check. Add the parts: 5 + 0.8 + 0.02 = 5.82. ✓
Watch out. Write 0.4 for 4 tenths, not 4. Write 0.05 for 5 hundredths, not 0.5.
0.06, 0.07, ?, 0.09, ?, ?, 0.12
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Find the jump. Then count on in hundredths, one jump at a time.
- Find the jump between two numbers you know. The numbers go up by the same amount each time.0.06 to 0.07: the jump is 0.01 (1 hundredth)
- Count on in hundredths. 10 hundredths make 1 tenth, so after 0.09 comes 0.10. And 100 hundredths make 1 whole, so after 0.99 comes 1.00.0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12
- Write the missing numbers. 0.08, 0.10, 0.11
Check. Count on again from the first number. The jump is always 0.01. ✓
Watch out. Keep two decimal places each time: write 0.10 (not 0.1) and 1.00 (not 1) in a hundredths sequence.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Work out what one gap is worth. Then count on from the left end.
- Find the two numbers at the ends and count the gaps. All the gaps on a number line are the same size.The line goes from 0.3 to 0.4 in 10 equal gaps.
- Work out what one gap is worth. Share the distance between the ends equally.0.1 ÷ 10 = 0.01
- Count the gaps from the left end to the point. Count the gaps, not the tick marks.The point is 7 gaps after 0.3.
- Work out the number. Start at the left end and add the gaps.0.3 + 7 × 0.01 = 0.3 + 0.07 = 0.37
Check. Count back from 0.4: 3 gaps back is 0.4 − 0.03 = 0.37. ✓
Watch out. Do not just read the nearest number on the line. Count the small gaps to find the exact value.
Watch out
Do not drop the zero. 7 hundredths is 0.07. If you write 0.7 you have written 7 tenths, which is ten times bigger. Also: after 0.09 comes 0.10 (10 hundredths), not 0.010.Exercise 6B Hundredths and place value
Non-calculatorKey words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. A hundred square has 100 small squares. Each is one hundredth. Count the shaded squares, then write the decimal.
- Count the small squares in the whole. There are 10 rows of 10 small squares. Each small square is one hundredth.10 × 10 = 100 squares
- Count the shaded squares. Count the full rows first (10 squares each), then the extra squares.2 full rows = 20 squares
20 + 3 = 23 squares - Write the fraction. The top number is the shaded squares.
23 100 - Write it as a decimal. Tenths are the first column after the point and hundredths are the second column.
ones tenths hundredths 0.23 0 . 2 3
23 hundredths = 0 ones, 2 tenths and 3 hundredths, so 0.23
Check. Go back: 0.23 is
Watch out. Each row of 10 squares is one tenth (0.1). Count in tens to be quick.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. A hundred square has 100 small squares. Each is one hundredth. Count the shaded squares, then write the decimal.
- Count the small squares in the whole. There are 10 rows of 10 small squares. Each small square is one hundredth.10 × 10 = 100 squares
- Count the shaded squares. Count the full rows first (10 squares each), then the extra squares.5 full rows = 50 squares
50 + 8 = 58 squares - Write the fraction. The top number is the shaded squares.
58 100 - Write it as a decimal. Tenths are the first column after the point and hundredths are the second column.
ones tenths hundredths 0.58 0 . 5 8
58 hundredths = 0 ones, 5 tenths and 8 hundredths, so 0.58
Check. Go back: 0.58 is
Watch out. Each row of 10 squares is one tenth (0.1). Count in tens to be quick.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. A hundred square has 100 small squares. Each is one hundredth. Count the shaded squares, then write the decimal.
- Count the small squares in the whole. There are 10 rows of 10 small squares. Each small square is one hundredth.10 × 10 = 100 squares
- Count the shaded squares. Count the shaded squares.7 squares
- Write the fraction. The top number is the shaded squares.
7 100 - Write it as a decimal. Tenths are the first column after the point and hundredths are the second column.
ones tenths hundredths 0.07 0 . 0 7
7 hundredths = 0 ones, 0 tenths and 7 hundredths, so 0.07
Check. Go back: 0.07 is
Watch out. Each row of 10 squares is one tenth (0.1). Count in tens to be quick.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 100 means hundredths. Tenths go in the first column after the point and hundredths in the second column.
is 9 hundredths.9 100 - Notice there are no tenths. 9 hundredths is less than 1 tenth (1 tenth = 10 hundredths). The tenths column must hold a 0.0 tenths and 9 hundredths
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths hundredths 0.09 0 . 0 9 - Write the decimal.
= 0.099 100
Check. Go back to a fraction: 0.09 =
Watch out. 7 hundredths is 0.07, not 0.7. The 0 in the tenths column keeps the 7 in the hundredths column.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 100 means hundredths. Tenths go in the first column after the point and hundredths in the second column.
is 45 hundredths.45 100 - Split the hundredths into tenths and hundredths. 10 hundredths make 1 tenth.45 hundredths = 4 tenths and 5 hundredths
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths hundredths 0.45 0 . 4 5 - Write the decimal.
= 0.4545 100
Check. Go back to a fraction: 0.45 =
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 100 means hundredths. Tenths go in the first column after the point and hundredths in the second column.
is 70 hundredths.70 100 - Split the hundredths into tenths and hundredths. 10 hundredths make 1 tenth.70 hundredths = 7 tenths and 0 hundredths
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths hundredths 0.70 0 . 7 0 - Write the decimal.
= 0.7070 100
Check. Go back to a fraction: 0.70 =
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 100 means hundredths. Tenths go in the first column after the point and hundredths in the second column.
is 3 hundredths.3 100 - Notice there are no tenths. 3 hundredths is less than 1 tenth (1 tenth = 10 hundredths). The tenths column must hold a 0.0 tenths and 3 hundredths
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths hundredths 0.03 0 . 0 3 - Write the decimal.
= 0.033 100
Check. Go back to a fraction: 0.03 =
Watch out. 7 hundredths is 0.07, not 0.7. The 0 in the tenths column keeps the 7 in the hundredths column.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 100 means hundredths. Tenths go in the first column after the point and hundredths in the second column.
is 99 hundredths.99 100 - Split the hundredths into tenths and hundredths. 10 hundredths make 1 tenth.99 hundredths = 9 tenths and 9 hundredths
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths hundredths 0.99 0 . 9 9 - Write the decimal.
= 0.9999 100
Check. Go back to a fraction: 0.99 =
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 100 means hundredths. Tenths go in the first column after the point and hundredths in the second column.
is 12 hundredths.12 100 - Split the hundredths into tenths and hundredths. 10 hundredths make 1 tenth.12 hundredths = 1 tenth and 2 hundredths
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths hundredths 0.12 0 . 1 2 - Write the decimal.
= 0.1212 100
Check. Go back to a fraction: 0.12 =
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.21 has 2 digits after the point, so the bottom number is 100.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 21, which is 21.
- Write the fraction. 0.21 =
(21 hundredths)21 100
Check. Go back:
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.08 has 2 digits after the point, so the bottom number is 100.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 08, which is 8.
- Write the fraction. 0.08 =
(8 hundredths)8 100
Check. Go back:
Watch out. For 0.05 the top number is 5, not 05. The bottom number is 100 because there are two digits after the point.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.60 has 2 digits after the point, so the bottom number is 100.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 60, which is 60.
- Write the fraction. 0.60 =
(60 hundredths)60 100
Check. Go back:
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.99 has 2 digits after the point, so the bottom number is 100.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 99, which is 99.
- Write the fraction. 0.99 =
(99 hundredths)99 100
Check. Go back:
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.35 has 2 digits after the point, so the bottom number is 100.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 35, which is 35.
- Write the fraction. 0.35 =
(35 hundredths)35 100
Check. Go back:
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.04 has 2 digits after the point, so the bottom number is 100.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 04, which is 4.
- Write the fraction. 0.04 =
(4 hundredths)4 100
Check. Go back:
Watch out. For 0.05 the top number is 5, not 05. The bottom number is 100 because there are two digits after the point.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Count the counters in each column. Each column has its own value.
- Count the counters in the ones column. Ones counters are worth 1 each.0 ones
- Count the counters in the tenths column. Tenths counters are worth 0.1 each.3 tenths
- Count the counters in the hundredths column. Hundredths counters are worth 0.01 each. If the column is empty, the digit is 0.4 hundredths
- Write the number. Put the digits in order with the decimal point after the ones.0 ones, 3 tenths and 4 hundredths = 0.34
Check. Read it back: 0.34 is 0 ones, 3 tenths and 4 hundredths. ✓
Watch out. An empty column means a 0 digit. Do not leave it out.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Count the counters in each column. Each column has its own value.
- Count the counters in the ones column. Ones counters are worth 1 each.1 one
- Count the counters in the tenths column. Tenths counters are worth 0.1 each.5 tenths
- Count the counters in the hundredths column. Hundredths counters are worth 0.01 each. If the column is empty, the digit is 0.2 hundredths
- Write the number. Put the digits in order with the decimal point after the ones.1 one, 5 tenths and 2 hundredths = 1.52
Check. Read it back: 1.52 is 1 one, 5 tenths and 2 hundredths. ✓
Watch out. An empty column means a 0 digit. Do not leave it out.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Count the counters in each column. Each column has its own value.
- Count the counters in the ones column. Ones counters are worth 1 each.2 ones
- Count the counters in the tenths column. Tenths counters are worth 0.1 each.0 tenths
- Count the counters in the hundredths column. Hundredths counters are worth 0.01 each. If the column is empty, the digit is 0.7 hundredths
- Write the number. Put the digits in order with the decimal point after the ones.2 ones, 0 tenths and 7 hundredths = 2.07
Check. Read it back: 2.07 is 2 ones, 0 tenths and 7 hundredths. ✓
Watch out. An empty column means a 0 digit. Do not leave it out.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Put each digit in its column of the place-value table. Write a 0 in any empty column. Then write the number with the point after the ones.
- Draw a place-value table. The columns are ones, then tenths, then hundredths.
ones tenths hundredths 4.26 4 . 2 6 - Write each digit in its column. A column with none in it still needs a 0 so the other digits stay in the right place.4 ones, 2 tenths and 6 hundredths
- Write the number. Put the decimal point between the ones and the tenths.4.26
Check. Read it back: 4.26 is 4 ones, 2 tenths and 6 hundredths. ✓
Watch out. Do not leave out a 0. Two ones, no tenths and 7 hundredths is 2.07, not 2.7.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Put each digit in its column of the place-value table. Write a 0 in any empty column. Then write the number with the point after the ones.
- Draw a place-value table. The columns are ones, then tenths, then hundredths.
ones tenths hundredths 0.09 0 . 0 9 - Write each digit in its column. A column with none in it still needs a 0 so the other digits stay in the right place.0 ones, 0 tenths and 9 hundredths
- Write the number. Put the decimal point between the ones and the tenths.0.09
Check. Read it back: 0.09 is 0 ones, 0 tenths and 9 hundredths. ✓
Watch out. Do not leave out a 0. Two ones, no tenths and 7 hundredths is 2.07, not 2.7.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Put each digit in its column of the place-value table. Write a 0 in any empty column. Then write the number with the point after the ones.
- Draw a place-value table. The columns are ones, then tenths, then hundredths.
ones tenths hundredths 7.05 7 . 0 5 - Write each digit in its column. A column with none in it still needs a 0 so the other digits stay in the right place.7 ones, 0 tenths and 5 hundredths
- Write the number. Put the decimal point between the ones and the tenths.7.05
Check. Read it back: 7.05 is 7 ones, 0 tenths and 5 hundredths. ✓
Watch out. Do not leave out a 0. Two ones, no tenths and 7 hundredths is 2.07, not 2.7.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Put each digit in its column of the place-value table. Write a 0 in any empty column. Then write the number with the point after the ones.
- Draw a place-value table. The columns are ones, then tenths, then hundredths.
ones tenths hundredths 2.91 2 . 9 1 - Write each digit in its column. A column with none in it still needs a 0 so the other digits stay in the right place.2 ones, 9 tenths and 1 hundredth
- Write the number. Put the decimal point between the ones and the tenths.2.91
Check. Read it back: 2.91 is 2 ones, 9 tenths and 1 hundredth. ✓
Watch out. Do not leave out a 0. Two ones, no tenths and 7 hundredths is 2.07, not 2.7.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Put each digit in its column of the place-value table. Write a 0 in any empty column. Then write the number with the point after the ones.
- Draw a place-value table. The columns are ones, then tenths, then hundredths.
ones tenths hundredths 0.60 0 . 6 0 - Write each digit in its column. A column with none in it still needs a 0 so the other digits stay in the right place.0 ones, 6 tenths and 0 hundredths
- Write the number. Put the decimal point between the ones and the tenths.0.60
Check. Read it back: 0.60 is 0 ones, 6 tenths and 0 hundredths. ✓
Watch out. Do not leave out a 0. Two ones, no tenths and 7 hundredths is 2.07, not 2.7.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Find which column the digit is in. The value is the digit times the value of that column.
- Write the number in a place-value table. This shows which column each digit is in.
ones tenths hundredths 3.47 3 . 4 7 - Find the column the digit is in. The columns, from the left, are tens, ones, then after the decimal point tenths and hundredths.The digit 7 is in the hundredths column.
- Work out its value. One hundredth is worth 0.01. The digit tells us how many of them there are.7 × 0.01 = 0.07
- Write the answer. 7 hundredths (0.07)
Check. Check by adding up all the parts: they should make 3.47. ✓
Watch out. The 0.5 in a number like 3.52 is worth 5 tenths (0.5), not 5 ones.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Find which column the digit is in. The value is the digit times the value of that column.
- Write the number in a place-value table. This shows which column each digit is in.
ones tenths hundredths 5.82 5 . 8 2 - Find the column the digit is in. The columns, from the left, are tens, ones, then after the decimal point tenths and hundredths.The digit 8 is in the tenths column.
- Work out its value. One tenth is worth 0.1. The digit tells us how many of them there are.8 × 0.1 = 0.8
- Write the answer. 8 tenths (0.8)
Check. Check by adding up all the parts: they should make 5.82. ✓
Watch out. The 0.5 in a number like 3.52 is worth 5 tenths (0.5), not 5 ones.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Find which column the digit is in. The value is the digit times the value of that column.
- Write the number in a place-value table. This shows which column each digit is in.
ones tenths hundredths 0.91 0 . 9 1 - Find the column the digit is in. The columns, from the left, are tens, ones, then after the decimal point tenths and hundredths.The digit 9 is in the tenths column.
- Work out its value. One tenth is worth 0.1. The digit tells us how many of them there are.9 × 0.1 = 0.9
- Write the answer. 9 tenths (0.9)
Check. Check by adding up all the parts: they should make 0.91. ✓
Watch out. The 0.5 in a number like 3.52 is worth 5 tenths (0.5), not 5 ones.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Find which column the digit is in. The value is the digit times the value of that column.
- Write the number in a place-value table. This shows which column each digit is in.
ones tenths hundredths 6.05 6 . 0 5 - Find the column the digit is in. The columns, from the left, are tens, ones, then after the decimal point tenths and hundredths.The digit 5 is in the hundredths column.
- Work out its value. One hundredth is worth 0.01. The digit tells us how many of them there are.5 × 0.01 = 0.05
- Write the answer. 5 hundredths (0.05)
Check. Check by adding up all the parts: they should make 6.05. ✓
Watch out. The 0.5 in a number like 3.52 is worth 5 tenths (0.5), not 5 ones.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Find which column the digit is in. The value is the digit times the value of that column.
- Write the number in a place-value table. This shows which column each digit is in.
ones tenths hundredths 7.28 7 . 2 8 - Find the column the digit is in. The columns, from the left, are tens, ones, then after the decimal point tenths and hundredths.The digit 7 is in the ones column.
- Work out its value. One one is worth 1. The digit tells us how many of them there are.7 × 1 = 7
- Write the answer. 7 ones (7)
Check. Check by adding up all the parts: they should make 7.28. ✓
Watch out. The 0.5 in a number like 3.52 is worth 5 tenths (0.5), not 5 ones.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Find which column the digit is in. The value is the digit times the value of that column.
- Write the number in a place-value table. This shows which column each digit is in.
tens ones tenths hundredths 12.34 1 2 . 3 4 - Find the column the digit is in. The columns, from the left, are tens, ones, then after the decimal point tenths and hundredths.The digit 1 is in the tens column.
- Work out its value. One ten is worth 10. The digit tells us how many of them there are.1 × 10 = 10
- Write the answer. 1 ten (10)
Check. Check by adding up all the parts: they should make 12.34. ✓
Watch out. The 0.5 in a number like 3.52 is worth 5 tenths (0.5), not 5 ones.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Count the columns from the decimal point to find the tenths column.
- Write the number in a place-value table. Each digit goes in its own column. The decimal point sits between the ones and the tenths.
ones tenths hundredths 6.72 6 . 7 2 - Find the tenths column. Tenths is the first column after the decimal point.The digit is 7.
Check. In 6.72 the digit 7 is worth 7 tenths. ✓
Watch out. Tenths is the FIRST digit after the point, hundredths is the SECOND.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Count the columns from the decimal point to find the hundredths column.
- Write the number in a place-value table. Each digit goes in its own column. The decimal point sits between the ones and the tenths.
ones tenths hundredths 0.58 0 . 5 8 - Find the hundredths column. Hundredths is the second column after the decimal point.The digit is 8.
Check. In 0.58 the digit 8 is worth 8 hundredths. ✓
Watch out. Tenths is the FIRST digit after the point, hundredths is the SECOND.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Count the columns from the decimal point to find the tenths column.
- Write the number in a place-value table. Each digit goes in its own column. The decimal point sits between the ones and the tenths.
ones tenths hundredths 9.04 9 . 0 4 - Find the tenths column. Tenths is the first column after the decimal point.The digit is 0.
Check. In 9.04 the digit 0 is worth 0 tenths. ✓
Watch out. Tenths is the FIRST digit after the point, hundredths is the SECOND.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Count the columns from the decimal point to find the hundredths column.
- Write the number in a place-value table. Each digit goes in its own column. The decimal point sits between the ones and the tenths.
ones tenths hundredths 3.19 3 . 1 9 - Find the hundredths column. Hundredths is the second column after the decimal point.The digit is 9.
Check. In 3.19 the digit 9 is worth 9 hundredths. ✓
Watch out. Tenths is the FIRST digit after the point, hundredths is the SECOND.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Split the number into the value of each digit and write them as an addition.
- Write the number in a place-value table.
ones tenths hundredths 3.45 3 . 4 5 - Work out the value of each digit. A zero digit is worth nothing, so we can leave it out.3 ones = 3
4 tenths = 0.4
5 hundredths = 0.05 - Write the parts as an addition. 3.45 = 3 + 0.4 + 0.05
Check. Add the parts: 3 + 0.4 + 0.05 = 3.45. ✓
Watch out. Write 0.4 for 4 tenths, not 4. Write 0.05 for 5 hundredths, not 0.5.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Split the number into the value of each digit and write them as an addition.
- Write the number in a place-value table.
ones tenths hundredths 6.08 6 . 0 8 - Work out the value of each digit. A zero digit is worth nothing, so we can leave it out.6 ones = 6
8 hundredths = 0.08 - Write the parts as an addition. 6.08 = 6 + 0.08
Check. Add the parts: 6 + 0.08 = 6.08. ✓
Watch out. Write 0.4 for 4 tenths, not 4. Write 0.05 for 5 hundredths, not 0.5.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Split the number into the value of each digit and write them as an addition.
- Write the number in a place-value table.
ones tenths hundredths 0.72 0 . 7 2 - Work out the value of each digit. A zero digit is worth nothing, so we can leave it out.7 tenths = 0.7
2 hundredths = 0.02 - Write the parts as an addition. 0.72 = 0.7 + 0.02
Check. Add the parts: 0.7 + 0.02 = 0.72. ✓
Watch out. Write 0.4 for 4 tenths, not 4. Write 0.05 for 5 hundredths, not 0.5.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Find the jump. Then count on in hundredths, one jump at a time.
- Find the jump between two numbers you know. The numbers go up by the same amount each time.0.04 to 0.05: the jump is 0.01 (1 hundredth)
- Count on in hundredths. 10 hundredths make 1 tenth, so after 0.09 comes 0.10. And 100 hundredths make 1 whole, so after 0.99 comes 1.00.0.04, 0.05, 0.06, 0.07, 0.08, 0.09
- Write the missing numbers. 0.06, 0.09
Check. Count on again from the first number. The jump is always 0.01. ✓
Watch out. Keep two decimal places each time: write 0.10 (not 0.1) and 1.00 (not 1) in a hundredths sequence.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Find the jump. Then count on in hundredths, one jump at a time.
- Find the jump between two numbers you know. The numbers go up by the same amount each time.0.97 to 0.98: the jump is 0.01 (1 hundredth)
- Count on in hundredths. 10 hundredths make 1 tenth, so after 0.09 comes 0.10. And 100 hundredths make 1 whole, so after 0.99 comes 1.00.0.97, 0.98, 0.99, 1.00, 1.01, 1.02
- Write the missing numbers. 0.99, 1.01
Check. Count on again from the first number. The jump is always 0.01. ✓
Watch out. Keep two decimal places each time: write 0.10 (not 0.1) and 1.00 (not 1) in a hundredths sequence.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Find the jump. Then count back in hundredths, one jump at a time.
- Find the jump between two numbers you know. The numbers go down by the same amount each time.0.13 to 0.12: the jump is 0.01 (1 hundredth)
- Count back in hundredths. Going back, 0.10 is the same as 10 hundredths, so before 0.10 comes 0.09. And 1.00 is 100 hundredths, so before 1.00 comes 0.99.0.13, 0.12, 0.11, 0.10, 0.09, 0.08
- Write the missing numbers. 0.11, 0.09
Check. Count back again from the first number. The jump is always 0.01. ✓
Watch out. Keep two decimal places each time: write 0.10 (not 0.1) and 1.00 (not 1) in a hundredths sequence.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Work out what one gap is worth. Then count on from the left end.
- Find the two numbers at the ends and count the gaps. All the gaps on a number line are the same size.The line goes from 0.5 to 0.6 in 10 equal gaps.
- Work out what one gap is worth. Share the distance between the ends equally.0.1 ÷ 10 = 0.01
- Count the gaps from the left end to the point. Count the gaps, not the tick marks.The point is 2 gaps after 0.5.
- Work out the number. Start at the left end and add the gaps.0.5 + 2 × 0.01 = 0.5 + 0.02 = 0.52
Check. Count back from 0.6: 8 gaps back is 0.6 − 0.08 = 0.52. ✓
Watch out. Do not just read the nearest number on the line. Count the small gaps to find the exact value.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Work out what one gap is worth. Then count on from the left end.
- Find the two numbers at the ends and count the gaps. All the gaps on a number line are the same size.The line goes from 0.5 to 0.6 in 10 equal gaps.
- Work out what one gap is worth. Share the distance between the ends equally.0.1 ÷ 10 = 0.01
- Count the gaps from the left end to the point. Count the gaps, not the tick marks.The point is 5 gaps after 0.5.
- Work out the number. Start at the left end and add the gaps.0.5 + 5 × 0.01 = 0.5 + 0.05 = 0.55
Check. Count back from 0.6: 5 gaps back is 0.6 − 0.05 = 0.55. ✓
Watch out. Do not just read the nearest number on the line. Count the small gaps to find the exact value.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Work out what one gap is worth. Then count on from the left end.
- Find the two numbers at the ends and count the gaps. All the gaps on a number line are the same size.The line goes from 0.5 to 0.6 in 10 equal gaps.
- Work out what one gap is worth. Share the distance between the ends equally.0.1 ÷ 10 = 0.01
- Count the gaps from the left end to the point. Count the gaps, not the tick marks.The point is 8 gaps after 0.5.
- Work out the number. Start at the left end and add the gaps.0.5 + 8 × 0.01 = 0.5 + 0.08 = 0.58
Check. Count back from 0.6: 2 gaps back is 0.6 − 0.02 = 0.58. ✓
Watch out. Do not just read the nearest number on the line. Count the small gaps to find the exact value.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Change each column into hundredths, then add them.
- Split the number into its columns. Each digit is worth a different amount.0.3 = 0 ones and 3 tenths
- Change each part into hundredths. 1 whole = 100 hundredths and 1 tenth = 10 hundredths.3 tenths = 3 × 10 = 30 hundredths
0 hundredths
0 + 30 + 0 = 30 hundredths - Write the answer. 30 hundredths
Check. 30 hundredths written as a decimal is 0.3. ✓
Watch out. 1 whole is 10 tenths, but it is 100 hundredths.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Change each column into hundredths, then add them.
- Split the number into its columns. Each digit is worth a different amount.0.8 = 0 ones and 8 tenths
- Change each part into hundredths. 1 whole = 100 hundredths and 1 tenth = 10 hundredths.8 tenths = 8 × 10 = 80 hundredths
0 hundredths
0 + 80 + 0 = 80 hundredths - Write the answer. 80 hundredths
Check. 80 hundredths written as a decimal is 0.8. ✓
Watch out. 1 whole is 10 tenths, but it is 100 hundredths.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Change each column into hundredths, then add them.
- Split the number into its columns. Each digit is worth a different amount.1.5 = 1 one and 5 tenths
- Change each part into hundredths. 1 whole = 100 hundredths and 1 tenth = 10 hundredths.1 whole one = 1 × 100 = 100 hundredths
5 tenths = 5 × 10 = 50 hundredths
0 hundredths
100 + 50 + 0 = 150 hundredths - Write the answer. 150 hundredths
Check. 150 hundredths written as a decimal is 1.5. ✓
Watch out. 1 whole is 10 tenths, but it is 100 hundredths.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Change each column into hundredths, then add them.
- Split the number into its columns. Each digit is worth a different amount.2.04 = 2 ones, 0 tenths and 4 hundredths
- Change each part into hundredths. 1 whole = 100 hundredths and 1 tenth = 10 hundredths.2 whole ones = 2 × 100 = 200 hundredths
0 tenths = 0 × 10 = 0 hundredths
4 hundredths
200 + 0 + 4 = 204 hundredths - Write the answer. 204 hundredths
Check. 204 hundredths written as a decimal is 2.04. ✓
Watch out. 1 whole is 10 tenths, but it is 100 hundredths.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. There are 100 cm in 1 m, so 1 cm is one hundredth of a metre.
- Write the length as hundredths of a metre. 1 cm is 1/100 m.17 cm =
m17 100 - Write it as a decimal. 17 hundredths: 0 ones, 1 tenth and 7 hundredths.
m = 0.17 m17 100
Check. 0.17 × 100 = 17. ✓
Watch out. Keep the unit. A small number of cm is a small part of a metre, so the decimal is less than 1.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. There are 100 cm in 1 m, so 1 cm is one hundredth of a metre.
- Write the length as hundredths of a metre. 1 cm is 1/100 m.4 cm =
m4 100 - Write it as a decimal. 4 hundredths: 0 ones, 0 tenths and 4 hundredths.
m = 0.04 m4 100
Check. 0.04 × 100 = 4. ✓
Watch out. Keep the unit. A small number of cm is a small part of a metre, so the decimal is less than 1.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. There are 100 cm in 1 m, so 1 cm is one hundredth of a metre.
- Write the length as hundredths of a metre. 1 cm is 1/100 m.85 cm =
m85 100 - Write it as a decimal. 85 hundredths: 0 ones, 8 tenths and 5 hundredths.
m = 0.85 m85 100
Check. 0.85 × 100 = 85. ✓
Watch out. Keep the unit. A small number of cm is a small part of a metre, so the decimal is less than 1.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Draw both numbers on hundred squares and compare how many squares are shaded.
- Shade 0.5. 0.5 is 5 tenths, which is 5 full rows.5 × 10 = 50 squares
- Shade 0.05. 0.05 is 5 hundredths, which is just 5 small squares.5 squares
- Compare. 50 squares is not the same as 5 squares, so 0.5 is ten times bigger.
0.5
0.05
Check. 0.05 × 10 = 0.5. ✓
Watch out. The 0 in 0.05 is in the tenths column, so the 5 is worth 5 hundredths.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. The number is between 0.3 and 0.4, so the tenths digit is 3. The hundredths digit is double the tenths digit.
- Find the tenths digit. Between 0.3 and 0.4 means 3 tenths and some hundredths.tenths digit = 3
- Find the hundredths digit. It is double the tenths digit.3 × 2 = 6
- Write the number. 0 ones, 3 tenths and 6 hundredths.0.36
Check. 0.36 is between 0.3 and 0.4 and 6 is double 3. ✓
Watch out. Check all the clues at the end.
Halves, quarters and three quarters
Printable: Worksheet (PDF) · Answers (PDF) · Open this lesson on its own page
Some fractions are used so often that it is worth knowing them as decimals. Use a hundred square. It has 100 small squares, and each one is 0.01.
- A half: cut the square into 2 equal parts. Each part is 100 ÷ 2 = 50 squares, so 1/2 = 50/100 = 0.5.
- A quarter: cut it into 4 equal parts. Each part is 100 ÷ 4 = 25 squares, so 1/4 = 25/100 = 0.25.
- Three quarters: 3 parts of 25 squares is 75 squares, so 3/4 = 75/100 = 0.75.
1/4 = 0.25
1/2 = 0.5
3/4 = 0.75
Why is a half 0.5 and also 0.50? A half is 5 tenths, 0.5. It is also 50 hundredths, 0.50. A 0 on the end of a decimal does not change the number, so 0.5 = 0.50.
Going the other way. To write 0.75 as a fraction, write it as hundredths: 75/100. Then divide the top and the bottom by 25: 75 ÷ 25 = 3 and 100 ÷ 25 = 4. So 0.75 = 3/4.
Money. There are 100p in £1. So a half of £1 is 50p = £0.50, a quarter of £1 is 25p = £0.25, and three quarters of £1 is 75p = £0.75.
Measures. We use these decimals for lengths, masses and capacities. 2.5 m is 2 and a half metres. 1.75 kg is 1 and three quarters of a kilogram. 0.25 litres is a quarter of a litre.
Key words. A hundred square has 100 small squares. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Key ideas
- 1/2 = 0.5 (also 0.50 and 5/10).
- 1/4 = 0.25 (25 hundredths).
- 3/4 = 0.75 (75 hundredths).
- A half of £1 is 50p = £0.50. A quarter is 25p. Three quarters is 75p.
- With a whole number: 2 1/2 = 2.5, 3 3/4 = 3.75.
- A decimal like 0.5 does not change if you add a 0 on the end: 0.5 = 0.50.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 4 equal parts.100 ÷ 4 = 25 squares in each part
- Find how many squares are in
. 1 part of 25 squares.1 4 1 part = 25 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=1 4 25 100 - Write it as a decimal. 25 hundredths is 0 ones, 2 tenths and 5 hundredths.
= 0.2525 100
Check. 25 × 4 = 100, so 4 equal parts of 25 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. 1/4 is 0.25, not 0.4 and not 0.14. A quarter is 25 hundredths.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 4 equal parts.100 ÷ 4 = 25 squares in each part
- Find how many squares are in
. 3 parts of 25 squares.3 4 3 × 25 = 75 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=3 4 75 100 - Write it as a decimal. 75 hundredths is 0 ones, 7 tenths and 5 hundredths.
= 0.7575 100
Check. 25 × 4 = 100, so 4 equal parts of 25 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. 1/4 is 0.25, not 0.4 and not 0.14. A quarter is 25 hundredths.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write the decimal as hundredths. Then divide the top and the bottom by the same number to make it simpler.
- Write the part after the point as hundredths. Two digits after the point mean the bottom number is 100. If there is only one digit, write a 0 after it first: 0.5 = 0.50.75 hundredths =
75 100 - Find a number that divides into the top and the bottom. The biggest one makes the fraction as simple as possible.75 and 100 both divide by 25.
- Divide the top and the bottom by it. Dividing both by the same number does not change the value.75 ÷ 25 = 3 and 100 ÷ 25 = 4
=75 100 3 4 - Write the fraction. 0.75 =
3 4
Check. Go back to a decimal:
Watch out. Do not forget to simplify: 0.75 is 3/4, and 75/100 is the same amount written in a longer way.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write the decimal as hundredths. Then divide the top and the bottom by the same number to make it simpler.
- Write the part after the point as hundredths. Two digits after the point mean the bottom number is 100. If there is only one digit, write a 0 after it first: 0.5 = 0.50.50 hundredths =
50 100 - Find a number that divides into the top and the bottom. The biggest one makes the fraction as simple as possible.50 and 100 both divide by 50.
- Divide the top and the bottom by it. Dividing both by the same number does not change the value.50 ÷ 50 = 1 and 100 ÷ 50 = 2
=50 100 1 2 - Write the fraction. 0.5 =
1 2
Check. Go back to a decimal:
Watch out. Do not forget to simplify: 0.75 is 3/4, and 75/100 is the same amount written in a longer way.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 4 equal parts.100 ÷ 4 = 25 squares in each part
- Find how many squares are in
. 1 part of 25 squares.1 4 1 part = 25 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=1 4 25 100 - Write it as a decimal. 25 hundredths is 0 ones, 2 tenths and 5 hundredths.
= 0.2525 100 - Add the whole number. The whole number goes in front of the point.2 + 0.25 = 2.25
Check. 25 × 4 = 100, so 4 equal parts of 25 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. 1/4 is 0.25, not 0.4 and not 0.14. A quarter is 25 hundredths.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write the decimal as hundredths. Then divide the top and the bottom by the same number to make it simpler.
- Write the part after the point as hundredths. Two digits after the point mean the bottom number is 100. If there is only one digit, write a 0 after it first: 0.5 = 0.50.75 hundredths =
75 100 - Find a number that divides into the top and the bottom. The biggest one makes the fraction as simple as possible.75 and 100 both divide by 25.
- Divide the top and the bottom by it. Dividing both by the same number does not change the value.75 ÷ 25 = 3 and 100 ÷ 25 = 4
=75 100 3 4 - Put the whole number in front. 1 and
= 1343 4 - Write the fraction. 1.75 = 134
Check. Go back to a decimal:
Watch out. Do not forget to simplify: 0.75 is 3/4, and 75/100 is the same amount written in a longer way.
Key words. Pence (p) are small amounts of money. 100 pence make 1 pound.
Method. Change the money into pence. Find a fraction of it: divide by the bottom number, then multiply by the top number. Change back to pounds.
- Change the pounds into pence. 1 pound is 100 pence, so we can divide the pence exactly.£2 = 2 × 100 = 200p
- Find one part: divide by the bottom number, 4. The bottom number says how many equal parts.200p ÷ 4 = 50p
- Multiply by the top number, 3. The top number says how many parts we take.50p × 3 = 150p
- Change back to pounds and pence. 100p = £1, so divide by 100. Always show two decimal places.150p = £1.50
Check. 50p × 4 = 200p, so 4 parts make the whole amount. ✓
Watch out. Write money with two decimal places: £3.50, not £3.5.
Watch out
1/4 is 0.25, not 0.4 or 0.14. A quarter is 25 hundredths. And 0.5 is not the same as 0.05: 0.5 is a half but 0.05 is only 5 hundredths. Do not forget: 3/4 is 0.75, so it is MORE than a half.Exercise 6C Halves, quarters and three quarters
Non-calculatorKey words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. A hundred square has 100 small squares. Each is one hundredth. Count the shaded squares, then write the decimal.
- Count the small squares in the whole. There are 10 rows of 10 small squares. Each small square is one hundredth.10 × 10 = 100 squares
- Count the shaded squares. Count the full rows first (10 squares each), then the extra squares.2 full rows = 20 squares
20 + 5 = 25 squares - Write the fraction. The top number is the shaded squares.
25 100 - Write it as a decimal. Tenths are the first column after the point and hundredths are the second column.
ones tenths hundredths 0.25 0 . 2 5
25 hundredths = 0 ones, 2 tenths and 5 hundredths, so 0.25
Check. Go back: 0.25 is
Watch out. Each row of 10 squares is one tenth (0.1). Count in tens to be quick.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. A hundred square has 100 small squares. Each is one hundredth. Count the shaded squares, then write the decimal.
- Count the small squares in the whole. There are 10 rows of 10 small squares. Each small square is one hundredth.10 × 10 = 100 squares
- Count the shaded squares. Count the full rows first (10 squares each), then the extra squares.5 full rows = 50 squares
- Write the fraction. The top number is the shaded squares.
50 100 - Write it as a decimal. Tenths are the first column after the point and hundredths are the second column.
ones tenths hundredths 0.50 0 . 5 0
50 hundredths = 0 ones and 5 tenths, so 0.5
Check. Go back: 0.5 is
Watch out. Each row of 10 squares is one tenth (0.1). Count in tens to be quick.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. A hundred square has 100 small squares. Each is one hundredth. Count the shaded squares, then write the decimal.
- Count the small squares in the whole. There are 10 rows of 10 small squares. Each small square is one hundredth.10 × 10 = 100 squares
- Count the shaded squares. Count the full rows first (10 squares each), then the extra squares.7 full rows = 70 squares
70 + 5 = 75 squares - Write the fraction. The top number is the shaded squares.
75 100 - Write it as a decimal. Tenths are the first column after the point and hundredths are the second column.
ones tenths hundredths 0.75 0 . 7 5
75 hundredths = 0 ones, 7 tenths and 5 hundredths, so 0.75
Check. Go back: 0.75 is
Watch out. Each row of 10 squares is one tenth (0.1). Count in tens to be quick.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 2 equal parts.100 ÷ 2 = 50 squares in each part
- Find how many squares are in
. 1 part of 50 squares.1 2 1 part = 50 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=1 2 50 100 - Write it as a decimal. 50 hundredths is 0 ones, 5 tenths and 0 hundredths. A trailing 0 in the hundredths column can be left out: 0.50 = 0.5.
= 0.5 (0.50)50 100
Check. 50 × 2 = 100, so 2 equal parts of 50 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. A half is 0.5 (5 tenths), which is the same as 0.50 (50 hundredths).
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 4 equal parts.100 ÷ 4 = 25 squares in each part
- Find how many squares are in
. 3 parts of 25 squares.3 4 3 × 25 = 75 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=3 4 75 100 - Write it as a decimal. 75 hundredths is 0 ones, 7 tenths and 5 hundredths.
= 0.7575 100
Check. 25 × 4 = 100, so 4 equal parts of 25 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. 1/4 is 0.25, not 0.4 and not 0.14. A quarter is 25 hundredths.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 4 equal parts.100 ÷ 4 = 25 squares in each part
- Find how many squares are in
. 1 part of 25 squares.1 4 1 part = 25 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=1 4 25 100 - Write it as a decimal. 25 hundredths is 0 ones, 2 tenths and 5 hundredths.
= 0.2525 100
Check. 25 × 4 = 100, so 4 equal parts of 25 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. 1/4 is 0.25, not 0.4 and not 0.14. A quarter is 25 hundredths.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 4 equal parts.100 ÷ 4 = 25 squares in each part
- Find how many squares are in
. 2 parts of 25 squares.2 4 2 × 25 = 50 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=2 4 50 100 - Write it as a decimal. 50 hundredths is 0 ones, 5 tenths and 0 hundredths. A trailing 0 in the hundredths column can be left out: 0.50 = 0.5.
= 0.5 (0.50)50 100
Check. 25 × 4 = 100, so 4 equal parts of 25 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. 1/4 is 0.25, not 0.4 and not 0.14. A quarter is 25 hundredths.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 10 means tenths. Tenths go in the first column after the decimal point.
is 5 tenths.5 10 - Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths 0.5 0 . 5 - Write the decimal.
= 0.55 10
Check. Go back to a fraction: 0.5 =
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 100 means hundredths. Tenths go in the first column after the point and hundredths in the second column.
is 25 hundredths.25 100 - Split the hundredths into tenths and hundredths. 10 hundredths make 1 tenth.25 hundredths = 2 tenths and 5 hundredths
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths hundredths 0.25 0 . 2 5 - Write the decimal.
= 0.2525 100
Check. Go back to a fraction: 0.25 =
Watch out. The bottom number tells you how many digits come after the point: 10 gives one digit, 100 gives two digits.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write the decimal as hundredths. Then divide the top and the bottom by the same number to make it simpler.
- Write the part after the point as hundredths. Two digits after the point mean the bottom number is 100. If there is only one digit, write a 0 after it first: 0.5 = 0.50.50 hundredths =
50 100 - Find a number that divides into the top and the bottom. The biggest one makes the fraction as simple as possible.50 and 100 both divide by 50.
- Divide the top and the bottom by it. Dividing both by the same number does not change the value.50 ÷ 50 = 1 and 100 ÷ 50 = 2
=50 100 1 2 - Write the fraction. 0.5 =
1 2
Check. Go back to a decimal:
Watch out. Do not forget to simplify: 0.75 is 3/4, and 75/100 is the same amount written in a longer way.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write the decimal as hundredths. Then divide the top and the bottom by the same number to make it simpler.
- Write the part after the point as hundredths. Two digits after the point mean the bottom number is 100. If there is only one digit, write a 0 after it first: 0.5 = 0.50.25 hundredths =
25 100 - Find a number that divides into the top and the bottom. The biggest one makes the fraction as simple as possible.25 and 100 both divide by 25.
- Divide the top and the bottom by it. Dividing both by the same number does not change the value.25 ÷ 25 = 1 and 100 ÷ 25 = 4
=25 100 1 4 - Write the fraction. 0.25 =
1 4
Check. Go back to a decimal:
Watch out. Do not forget to simplify: 0.75 is 3/4, and 75/100 is the same amount written in a longer way.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write the decimal as hundredths. Then divide the top and the bottom by the same number to make it simpler.
- Write the part after the point as hundredths. Two digits after the point mean the bottom number is 100. If there is only one digit, write a 0 after it first: 0.5 = 0.50.75 hundredths =
75 100 - Find a number that divides into the top and the bottom. The biggest one makes the fraction as simple as possible.75 and 100 both divide by 25.
- Divide the top and the bottom by it. Dividing both by the same number does not change the value.75 ÷ 25 = 3 and 100 ÷ 25 = 4
=75 100 3 4 - Write the fraction. 0.75 =
3 4
Check. Go back to a decimal:
Watch out. Do not forget to simplify: 0.75 is 3/4, and 75/100 is the same amount written in a longer way.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.1 has 1 digit after the point, so the bottom number is 10.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 1, which is 1.
- Write the fraction. 0.1 =
(1 tenth)1 10
Check. Go back:
Watch out. The number of digits after the decimal point matches the number of zeros in the bottom number.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the digits after the point to find the bottom number (10 or 100). Write those digits as the top number. Put any whole number in front.
- Count the digits after the decimal point. One digit after the point means tenths. Two digits mean hundredths.0.01 has 2 digits after the point, so the bottom number is 100.
- Read the digits after the point as one number. This is the top number. Ignore any 0 at the front.The digits after the point are 01, which is 1.
- Write the fraction. 0.01 =
(1 hundredth)1 100
Check. Go back:
Watch out. For 0.05 the top number is 5, not 05. The bottom number is 100 because there are two digits after the point.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write the decimal as hundredths. Then divide the top and the bottom by the same number to make it simpler.
- Write the part after the point as hundredths. Two digits after the point mean the bottom number is 100. If there is only one digit, write a 0 after it first: 0.5 = 0.50.50 hundredths =
50 100 - Find a number that divides into the top and the bottom. The biggest one makes the fraction as simple as possible.50 and 100 both divide by 50.
- Divide the top and the bottom by it. Dividing both by the same number does not change the value.50 ÷ 50 = 1 and 100 ÷ 50 = 2
=50 100 1 2 - Write the fraction. 0.5 =
1 2
Check. Go back to a decimal:
Watch out. Do not forget to simplify: 0.75 is 3/4, and 75/100 is the same amount written in a longer way.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 2 equal parts.100 ÷ 2 = 50 squares in each part
- Find how many squares are in
. 1 part of 50 squares.1 2 1 part = 50 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=1 2 50 100 - Write it as a decimal. 50 hundredths is 0 ones, 5 tenths and 0 hundredths. A trailing 0 in the hundredths column can be left out: 0.50 = 0.5.
= 0.5 (0.50)50 100 - Add the whole number. The whole number goes in front of the point.2 + 0.5 = 2.5
Check. 50 × 2 = 100, so 2 equal parts of 50 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. A half is 0.5 (5 tenths), which is the same as 0.50 (50 hundredths).
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 4 equal parts.100 ÷ 4 = 25 squares in each part
- Find how many squares are in
. 3 parts of 25 squares.3 4 3 × 25 = 75 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=3 4 75 100 - Write it as a decimal. 75 hundredths is 0 ones, 7 tenths and 5 hundredths.
= 0.7575 100 - Add the whole number. The whole number goes in front of the point.3 + 0.75 = 3.75
Check. 25 × 4 = 100, so 4 equal parts of 25 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. 1/4 is 0.25, not 0.4 and not 0.14. A quarter is 25 hundredths.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 4 equal parts.100 ÷ 4 = 25 squares in each part
- Find how many squares are in
. 1 part of 25 squares.1 4 1 part = 25 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=1 4 25 100 - Write it as a decimal. 25 hundredths is 0 ones, 2 tenths and 5 hundredths.
= 0.2525 100 - Add the whole number. The whole number goes in front of the point.1 + 0.25 = 1.25
Check. 25 × 4 = 100, so 4 equal parts of 25 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. 1/4 is 0.25, not 0.4 and not 0.14. A quarter is 25 hundredths.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 2 equal parts.100 ÷ 2 = 50 squares in each part
- Find how many squares are in
. 1 part of 50 squares.1 2 1 part = 50 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=1 2 50 100 - Write it as a decimal. 50 hundredths is 0 ones, 5 tenths and 0 hundredths. A trailing 0 in the hundredths column can be left out: 0.50 = 0.5.
= 0.5 (0.50)50 100 - Add the whole number. The whole number goes in front of the point.6 + 0.5 = 6.5
Check. 50 × 2 = 100, so 2 equal parts of 50 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. A half is 0.5 (5 tenths), which is the same as 0.50 (50 hundredths).
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write the decimal as hundredths. Then divide the top and the bottom by the same number to make it simpler.
- Write the part after the point as hundredths. Two digits after the point mean the bottom number is 100. If there is only one digit, write a 0 after it first: 0.5 = 0.50.50 hundredths =
50 100 - Find a number that divides into the top and the bottom. The biggest one makes the fraction as simple as possible.50 and 100 both divide by 50.
- Divide the top and the bottom by it. Dividing both by the same number does not change the value.50 ÷ 50 = 1 and 100 ÷ 50 = 2
=50 100 1 2 - Put the whole number in front. 2 and
= 2121 2 - Write the fraction. 2.5 = 212
Check. Go back to a decimal:
Watch out. Do not forget to simplify: 0.75 is 3/4, and 75/100 is the same amount written in a longer way.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write the decimal as hundredths. Then divide the top and the bottom by the same number to make it simpler.
- Write the part after the point as hundredths. Two digits after the point mean the bottom number is 100. If there is only one digit, write a 0 after it first: 0.5 = 0.50.75 hundredths =
75 100 - Find a number that divides into the top and the bottom. The biggest one makes the fraction as simple as possible.75 and 100 both divide by 25.
- Divide the top and the bottom by it. Dividing both by the same number does not change the value.75 ÷ 25 = 3 and 100 ÷ 25 = 4
=75 100 3 4 - Put the whole number in front. 4 and
= 4343 4 - Write the fraction. 4.75 = 434
Check. Go back to a decimal:
Watch out. Do not forget to simplify: 0.75 is 3/4, and 75/100 is the same amount written in a longer way.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write the decimal as hundredths. Then divide the top and the bottom by the same number to make it simpler.
- Write the part after the point as hundredths. Two digits after the point mean the bottom number is 100. If there is only one digit, write a 0 after it first: 0.5 = 0.50.25 hundredths =
25 100 - Find a number that divides into the top and the bottom. The biggest one makes the fraction as simple as possible.25 and 100 both divide by 25.
- Divide the top and the bottom by it. Dividing both by the same number does not change the value.25 ÷ 25 = 1 and 100 ÷ 25 = 4
=25 100 1 4 - Put the whole number in front. 1 and
= 1141 4 - Write the fraction. 1.25 = 114
Check. Go back to a decimal:
Watch out. Do not forget to simplify: 0.75 is 3/4, and 75/100 is the same amount written in a longer way.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write the decimal as hundredths. Then divide the top and the bottom by the same number to make it simpler.
- Write the part after the point as hundredths. Two digits after the point mean the bottom number is 100. If there is only one digit, write a 0 after it first: 0.5 = 0.50.50 hundredths =
50 100 - Find a number that divides into the top and the bottom. The biggest one makes the fraction as simple as possible.50 and 100 both divide by 50.
- Divide the top and the bottom by it. Dividing both by the same number does not change the value.50 ÷ 50 = 1 and 100 ÷ 50 = 2
=50 100 1 2 - Put the whole number in front. 7 and
= 7121 2 - Write the fraction. 7.5 = 712
Check. Go back to a decimal:
Watch out. Do not forget to simplify: 0.75 is 3/4, and 75/100 is the same amount written in a longer way.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write the decimal as hundredths. Then divide the top and the bottom by the same number to make it simpler.
- Write the part after the point as hundredths. Two digits after the point mean the bottom number is 100. If there is only one digit, write a 0 after it first: 0.5 = 0.50.25 hundredths =
25 100 - Find a number that divides into the top and the bottom. The biggest one makes the fraction as simple as possible.25 and 100 both divide by 25.
- Divide the top and the bottom by it. Dividing both by the same number does not change the value.25 ÷ 25 = 1 and 100 ÷ 25 = 4
=25 100 1 4 - Put the whole number in front. 3 and
= 3141 4 - Write the fraction. 3.25 = 314
Check. Go back to a decimal:
Watch out. Do not forget to simplify: 0.75 is 3/4, and 75/100 is the same amount written in a longer way.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Work out what one gap is worth. Then count on from the left end.
- Find the two numbers at the ends and count the gaps. All the gaps on a number line are the same size.The line goes from 0 to 1 in 4 equal gaps.
- Work out what one gap is worth. Share the distance between the ends equally.1 ÷ 4 = 0.25
- Count the gaps from the left end to the point. Count the gaps, not the tick marks.The point is 1 gap after 0.
- Work out the number. Start at the left end and add the gaps.0 + 1 × 0.25 = 0 + 0.25 = 0.25
Check. Count back from 1: 3 gaps back is 1 − 0.75 = 0.25. ✓
Watch out. Do not just read the nearest number on the line. Count the small gaps to find the exact value.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Work out what one gap is worth. Then count on from the left end.
- Find the two numbers at the ends and count the gaps. All the gaps on a number line are the same size.The line goes from 0 to 1 in 4 equal gaps.
- Work out what one gap is worth. Share the distance between the ends equally.1 ÷ 4 = 0.25
- Count the gaps from the left end to the point. Count the gaps, not the tick marks.The point is 2 gaps after 0.
- Work out the number. Start at the left end and add the gaps.0 + 2 × 0.25 = 0 + 0.50 = 0.50
Check. Count back from 1: 2 gaps back is 1 − 0.50 = 0.50. ✓
Watch out. Do not just read the nearest number on the line. Count the small gaps to find the exact value.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Work out what one gap is worth. Then count on from the left end.
- Find the two numbers at the ends and count the gaps. All the gaps on a number line are the same size.The line goes from 0 to 1 in 4 equal gaps.
- Work out what one gap is worth. Share the distance between the ends equally.1 ÷ 4 = 0.25
- Count the gaps from the left end to the point. Count the gaps, not the tick marks.The point is 3 gaps after 0.
- Work out the number. Start at the left end and add the gaps.0 + 3 × 0.25 = 0 + 0.75 = 0.75
Check. Count back from 1: 1 gap back is 1 − 0.25 = 0.75. ✓
Watch out. Do not just read the nearest number on the line. Count the small gaps to find the exact value.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 2 equal parts.100 ÷ 2 = 50 squares in each part
- Find how many squares are in
. 1 part of 50 squares.1 2 1 part = 50 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=1 2 50 100 - Write it as a decimal. 50 hundredths is 0 ones, 5 tenths and 0 hundredths. A trailing 0 in the hundredths column can be left out: 0.50 = 0.5.
= 0.5 (0.50)50 100 m = 0.5 m1 2
Check. 50 × 2 = 100, so 2 equal parts of 50 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. A half is 0.5 (5 tenths), which is the same as 0.50 (50 hundredths).
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 4 equal parts.100 ÷ 4 = 25 squares in each part
- Find how many squares are in
. 3 parts of 25 squares.3 4 3 × 25 = 75 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=3 4 75 100 - Write it as a decimal. 75 hundredths is 0 ones, 7 tenths and 5 hundredths.
= 0.7575 100 kg = 0.75 kg3 4
Check. 25 × 4 = 100, so 4 equal parts of 25 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. 1/4 is 0.25, not 0.4 and not 0.14. A quarter is 25 hundredths.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 4 equal parts.100 ÷ 4 = 25 squares in each part
- Find how many squares are in
. 1 part of 25 squares.1 4 1 part = 25 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=1 4 25 100 - Write it as a decimal. 25 hundredths is 0 ones, 2 tenths and 5 hundredths.
= 0.2525 100 - Add the whole number. The whole number goes in front of the point.1 + 0.25 = 1.25
114 litres = 1.25 litres
Check. 25 × 4 = 100, so 4 equal parts of 25 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. 1/4 is 0.25, not 0.4 and not 0.14. A quarter is 25 hundredths.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 2 equal parts.100 ÷ 2 = 50 squares in each part
- Find how many squares are in
. 1 part of 50 squares.1 2 1 part = 50 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=1 2 50 100 - Write it as a decimal. 50 hundredths is 0 ones, 5 tenths and 0 hundredths. A trailing 0 in the hundredths column can be left out: 0.50 = 0.5.
= 0.5 (0.50)50 100 - Add the whole number. The whole number goes in front of the point.2 + 0.5 = 2.5
212 km = 2.5 km
Check. 50 × 2 = 100, so 2 equal parts of 50 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. A half is 0.5 (5 tenths), which is the same as 0.50 (50 hundredths).
Key words. Pence (p) are small amounts of money. 100 pence make 1 pound.
Method. Change the money into pence. Find a fraction of it: divide by the bottom number, then multiply by the top number. Change back to pounds.
- Change the pounds into pence. 1 pound is 100 pence, so we can divide the pence exactly.£1 = 1 × 100 = 100p
- Find one part: divide by the bottom number, 2. The bottom number says how many equal parts.100p ÷ 2 = 50p
- Change back to pounds and pence. 100p = £1, so divide by 100. Always show two decimal places.50p = £0.50
Check. 50p × 2 = 100p, so 2 parts make the whole amount. ✓
Watch out. Write money with two decimal places: £3.50, not £3.5.
Key words. Pence (p) are small amounts of money. 100 pence make 1 pound.
Method. Change the money into pence. Find a fraction of it: divide by the bottom number, then multiply by the top number. Change back to pounds.
- Change the pounds into pence. 1 pound is 100 pence, so we can divide the pence exactly.£2 = 2 × 100 = 200p
- Find one part: divide by the bottom number, 4. The bottom number says how many equal parts.200p ÷ 4 = 50p
- Change back to pounds and pence. 100p = £1, so divide by 100. Always show two decimal places.50p = £0.50
Check. 50p × 4 = 200p, so 4 parts make the whole amount. ✓
Watch out. Write money with two decimal places: £3.50, not £3.5.
Key words. Pence (p) are small amounts of money. 100 pence make 1 pound.
Method. Change the money into pence. Find a fraction of it: divide by the bottom number, then multiply by the top number. Change back to pounds.
- Change the pounds into pence. 1 pound is 100 pence, so we can divide the pence exactly.£4 = 4 × 100 = 400p
- Find one part: divide by the bottom number, 4. The bottom number says how many equal parts.400p ÷ 4 = 100p
- Multiply by the top number, 3. The top number says how many parts we take.100p × 3 = 300p
- Change back to pounds and pence. 100p = £1, so divide by 100. Always show two decimal places.300p = £3.00
Check. 100p × 4 = 400p, so 4 parts make the whole amount. ✓
Watch out. Write money with two decimal places: £3.50, not £3.5.
Key words. Pence (p) are small amounts of money. 100 pence make 1 pound.
Method. Change the money into pence. Find a fraction of it: divide by the bottom number, then multiply by the top number. Change back to pounds.
- Change the pounds into pence. 1 pound is 100 pence, so we can divide the pence exactly.£5 = 5 × 100 = 500p
- Find one part: divide by the bottom number, 2. The bottom number says how many equal parts.500p ÷ 2 = 250p
- Change back to pounds and pence. 100p = £1, so divide by 100. Always show two decimal places.250p = £2.50
Check. 250p × 2 = 500p, so 2 parts make the whole amount. ✓
Watch out. Write money with two decimal places: £3.50, not £3.5.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 4 equal parts.100 ÷ 4 = 25 squares in each part
- Find how many squares are in
. 1 part of 25 squares.1 4 1 part = 25 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=1 4 25 100 - Write it as a decimal. 25 hundredths is 0 ones, 2 tenths and 5 hundredths.
= 0.2525 100 litre = 0.25 litre1 4
Check. 25 × 4 = 100, so 4 equal parts of 25 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. 1/4 is 0.25, not 0.4 and not 0.14. A quarter is 25 hundredths.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 4 equal parts.100 ÷ 4 = 25 squares in each part
- Find how many squares are in
. 3 parts of 25 squares.3 4 3 × 25 = 75 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=3 4 75 100 - Write it as a decimal. 75 hundredths is 0 ones, 7 tenths and 5 hundredths.
= 0.7575 100 litre = 0.75 litre3 4
Check. 25 × 4 = 100, so 4 equal parts of 25 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. 1/4 is 0.25, not 0.4 and not 0.14. A quarter is 25 hundredths.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Use a hundred square. Cut it into equal parts to find how many hundredths the fraction is worth. Then write it as a decimal.
- Think of a hundred square. It has 100 small squares, and each is 1 hundredth. Cut it into 4 equal parts.100 ÷ 4 = 25 squares in each part
- Find how many squares are in
. 3 parts of 25 squares.3 4 3 × 25 = 75 squares - Write it as hundredths. The bottom number is 100 because the square has 100 squares.
=3 4 75 100 - Write it as a decimal. 75 hundredths is 0 ones, 7 tenths and 5 hundredths.
= 0.7575 100 - Add the whole number. The whole number goes in front of the point.2 + 0.75 = 2.75
234 m = 2.75 m
Check. 25 × 4 = 100, so 4 equal parts of 25 squares fill the whole hundred square. Known facts: 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75. ✓
Watch out. 1/4 is 0.25, not 0.4 and not 0.14. A quarter is 25 hundredths.
Key words. Lengths, masses and capacities can be written as decimals: 2.5 m is two and a half metres, 1.75 kg is 1 and 3/4 kilograms. Line up the decimal points to add or subtract.
Method. Take the 1 m away from the whole number part. The 0.75 stays the same.
- Split 2.75 m. 2.75 = 2 + 0.752.75 m = 2 m + 0.75 m
- Take away 1 m from the whole metres. Only the 2 changes.2 − 1 = 1
- Put the parts together. The 0.75 is not changed.1 + 0.75 = 1.75 m
Check. 1.75 + 1 = 2.75. ✓
Watch out. Only subtract from the whole metres.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Check what 1/4 really is. A quarter is 1 of 4 equal parts of 100 squares.
- Work out a quarter of 100. A hundred square has 100 squares.100 ÷ 4 = 25 squares
- Write the quarter as a decimal. 25 hundredths is 0.25.
= 0.2525 100 - Compare with Tom’s answer. Tom used the 4 from the bottom of the fraction and put it after the point.0.4 is 4 tenths (
), which is less than a half. A quarter is not 0.4.4 10
Check. 0.25 × 4 = 1. ✓
Watch out. The bottom number of a fraction is not a digit of the decimal.
Decimals: 0.1 0.25 0.5 0.75
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write each fraction as a decimal. Then match it to the list.
- A: a half. 5 tenths.
= 0.51 2 - B: three quarters. 75 hundredths.
= 0.753 4 - C: a quarter. 25 hundredths.
= 0.251 4 - D: a tenth. 1 tenth.
= 0.11 10 - Write the matches. A and 0.5, B and 0.75, C and 0.25, D and 0.1
Check. Each fraction was matched with a different decimal. ✓
Watch out. Use the hundred square: 25, 50 and 75 squares.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write each as a decimal and look for the one with a different value.
- Write each as a decimal. 1/2 and 5/10 are both 0.5.0.5 = 0.5
= 0.55 10 = 0.5 0.05 = 5 hundredths1 2 - Find the odd one out. 0.05 has a 0 in the tenths column. It is much smaller.0.05
Check. 0.05 is 5 hundredths and a half is 50 hundredths. ✓
Watch out. 0.5 and 0.05 are different numbers.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Try the fractions with 4 on the bottom. Find the one that is more than a half and less than 1.
- List fractions with a bottom number of 4. Quarters: 1/4, 2/4, 3/4.
= 0.25,1 4 = 0.5,2 4 = 0.753 4 - Find the one between 0.5 and 1. It must be more than 0.5 and less than 1.0.75 is more than 0.5 and less than 1.
- Write it both ways.
= 0.753 4
Check. 0.5 < 0.75 < 1. ✓
Watch out. 2/4 is exactly a half, so it is not bigger than a half.
Dividing by 10 and 100
Printable: Worksheet (PDF) · Answers (PDF) · Open this lesson on its own page
When you divide by 10, the number gets 10 times smaller. Every digit moves one column to the right. When you divide by 100, every digit moves two columns to the right. The digits are the ones that move. The decimal point stays where it is.
Dividing by 100. Move the digits two columns.
Fill the gaps with zeros. 7 ÷ 10 = 0.7 and 7 ÷ 100 = 0.07. In 0.07 there are 0 ones and 0 tenths, so both columns need a 0.
Tidying up. 40 ÷ 10 = 4.0, and 4.0 is just 4. And 30 ÷ 100 = 0.30, which is 0.3. The last 0 is not needed.
Why? Dividing by 100 is the same as dividing by 10 twice. 53 ÷ 10 = 5.3 and then 5.3 ÷ 10 = 0.53. The opposite is multiplying: 0.53 × 100 = 53. The digits move left.
Measures. There are 100 cm in 1 m. To change cm to m, divide by 100: 250 cm ÷ 100 = 2.5 m. There are 10 mm in 1 cm, so to change mm to cm, divide by 10: 36 mm ÷ 10 = 3.6 cm. Money. There are 100p in £1, so 450p ÷ 100 = £4.50.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move to the right.
Key ideas
- ÷ 10: every digit moves 1 column to the right.
- ÷ 100: every digit moves 2 columns to the right.
- Put a 0 in any empty column: 7 ÷ 100 = 0.07.
- Dividing by 100 is the same as dividing by 10 twice.
- The opposite of dividing is multiplying: the digits move left.
- cm ÷ 100 = m, mm ÷ 10 = cm, p ÷ 100 = £.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 10 moves each digit 1 place to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 10 makes every digit 10 times smaller.
- Move every digit 1 column to the right. Each digit slides one column to the right, to a column that is worth 10 times less.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.6 ÷ 10 = 0.6
Check. Go the other way: 0.6 × 10 = 6. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 10 moves each digit 1 place to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 10 makes every digit 10 times smaller.
- Move every digit 1 column to the right. Each digit slides one column to the right, to a column that is worth 10 times less.
- Write the answer. Put the decimal point after the ones.48 ÷ 10 = 4.8
Check. Go the other way: 4.8 × 10 = 48. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 100 moves each digit 2 places to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 100 makes every digit 100 times smaller.
- Move every digit 2 columns to the right. Each digit slides two columns to the right, because dividing by 100 is dividing by 10 twice.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.48 ÷ 100 = 0.48
Check. Go the other way: 0.48 × 100 = 48. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 100 moves each digit 2 places to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 100 makes every digit 100 times smaller.
- Move every digit 2 columns to the right. Each digit slides two columns to the right, because dividing by 100 is dividing by 10 twice.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.7 ÷ 100 = 0.07
Check. Go the other way: 0.07 × 100 = 7. ✓
Watch out. The digits move, not the decimal point. And 5 ÷ 100 is 0.05: you need a 0 in the tenths column as well as the ones column.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 100 moves each digit 2 places to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 100 makes every digit 100 times smaller.
- Move every digit 2 columns to the right. Each digit slides two columns to the right, because dividing by 100 is dividing by 10 twice.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones. The last 0 is not needed: 4.0 is the same as 4, and 0.30 is the same as 0.3.30 ÷ 100 = 0.3
Check. Go the other way: 0.3 × 100 = 30. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Use the opposite operation. The opposite of dividing is multiplying.
- Think about the opposite operation. The opposite of dividing by 10 is multiplying by 10.? = 3.6 × 10
- Move every digit 1 column to the left. Multiplying makes each digit bigger, so the digits move left.3.6 × 10 = 36
- Write the answer. 36 ÷ 10 = 3.6
Check. Check: 36 ÷ 10 = 3.6. ✓
Watch out. Dividing moves digits right. To undo it, move them left.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Count how many columns the digits moved to the right. One column is ÷ 10 and two columns is ÷ 100.
- Compare the two numbers. 52 became 0.52.52 → 0.52
- Count how many columns the digits moved. Each digit moved to the right.The digits moved 2 columns to the right.
- Decide what we divided by. 1 column means ÷ 10. 2 columns means ÷ 100.100
Check. Check: 52 ÷ 100 = 0.52. ✓
Watch out. Compare where the digits are, not how long the number looks.
Key words. Convert means change from one unit to another. 1 m = 100 cm. 1 cm = 10 mm.
Method. There are 100 cm in 1 m. Divide by 100 to change cm into m.
- Find how many of the small unit make one of the big unit. We need this to change units.1 m = 100 cm
- Choose the operation. We are changing cm into m. A m is bigger, so we need fewer of them: divide by 100.340 ÷ 100
- Move the digits 2 columns to the right. Dividing by 100 makes each digit 100 times smaller.340 ÷ 100 = 3.4
- Write the answer with the unit. 340 cm = 3.4 m
Check. Go back: 3.4 × 100 = 340. ✓
Watch out. Fewer m than cm: the number should get smaller. If it does not, you used the wrong operation.
Watch out
The digits move. You do not just add a point. 7 ÷ 100 is 0.07, not 0.7 and not 7.00. Also, dividing makes the number SMALLER, so the digits must move to the right. If the answer is bigger than what you started with, something has gone wrong.Exercise 6D Dividing by 10 and 100
Non-calculatorKey words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 10 moves each digit 1 place to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 10 makes every digit 10 times smaller.
- Move every digit 1 column to the right. Each digit slides one column to the right, to a column that is worth 10 times less.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.3 ÷ 10 = 0.3
Check. Go the other way: 0.3 × 10 = 3. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 10 moves each digit 1 place to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 10 makes every digit 10 times smaller.
- Move every digit 1 column to the right. Each digit slides one column to the right, to a column that is worth 10 times less.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.9 ÷ 10 = 0.9
Check. Go the other way: 0.9 × 10 = 9. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 10 moves each digit 1 place to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 10 makes every digit 10 times smaller.
- Move every digit 1 column to the right. Each digit slides one column to the right, to a column that is worth 10 times less.
- Write the answer. Put the decimal point after the ones. The last 0 is not needed: 4.0 is the same as 4, and 0.30 is the same as 0.3.20 ÷ 10 = 2
Check. Go the other way: 2 × 10 = 20. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 10 moves each digit 1 place to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 10 makes every digit 10 times smaller.
- Move every digit 1 column to the right. Each digit slides one column to the right, to a column that is worth 10 times less.
- Write the answer. Put the decimal point after the ones.45 ÷ 10 = 4.5
Check. Go the other way: 4.5 × 10 = 45. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 10 moves each digit 1 place to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 10 makes every digit 10 times smaller.
- Move every digit 1 column to the right. Each digit slides one column to the right, to a column that is worth 10 times less.
- Write the answer. Put the decimal point after the ones. The last 0 is not needed: 4.0 is the same as 4, and 0.30 is the same as 0.3.70 ÷ 10 = 7
Check. Go the other way: 7 × 10 = 70. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 10 moves each digit 1 place to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 10 makes every digit 10 times smaller.
- Move every digit 1 column to the right. Each digit slides one column to the right, to a column that is worth 10 times less.
- Write the answer. Put the decimal point after the ones.86 ÷ 10 = 8.6
Check. Go the other way: 8.6 × 10 = 86. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 100 moves each digit 2 places to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 100 makes every digit 100 times smaller.
- Move every digit 2 columns to the right. Each digit slides two columns to the right, because dividing by 100 is dividing by 10 twice.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.4 ÷ 100 = 0.04
Check. Go the other way: 0.04 × 100 = 4. ✓
Watch out. The digits move, not the decimal point. And 5 ÷ 100 is 0.05: you need a 0 in the tenths column as well as the ones column.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 100 moves each digit 2 places to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 100 makes every digit 100 times smaller.
- Move every digit 2 columns to the right. Each digit slides two columns to the right, because dividing by 100 is dividing by 10 twice.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.8 ÷ 100 = 0.08
Check. Go the other way: 0.08 × 100 = 8. ✓
Watch out. The digits move, not the decimal point. And 5 ÷ 100 is 0.05: you need a 0 in the tenths column as well as the ones column.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 100 moves each digit 2 places to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 100 makes every digit 100 times smaller.
- Move every digit 2 columns to the right. Each digit slides two columns to the right, because dividing by 100 is dividing by 10 twice.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones. The last 0 is not needed: 4.0 is the same as 4, and 0.30 is the same as 0.3.60 ÷ 100 = 0.6
Check. Go the other way: 0.6 × 100 = 60. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 100 moves each digit 2 places to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 100 makes every digit 100 times smaller.
- Move every digit 2 columns to the right. Each digit slides two columns to the right, because dividing by 100 is dividing by 10 twice.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.37 ÷ 100 = 0.37
Check. Go the other way: 0.37 × 100 = 37. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 100 moves each digit 2 places to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 100 makes every digit 100 times smaller.
- Move every digit 2 columns to the right. Each digit slides two columns to the right, because dividing by 100 is dividing by 10 twice.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones. The last 0 is not needed: 4.0 is the same as 4, and 0.30 is the same as 0.3.90 ÷ 100 = 0.9
Check. Go the other way: 0.9 × 100 = 90. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 100 moves each digit 2 places to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 100 makes every digit 100 times smaller.
- Move every digit 2 columns to the right. Each digit slides two columns to the right, because dividing by 100 is dividing by 10 twice.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.52 ÷ 100 = 0.52
Check. Go the other way: 0.52 × 100 = 52. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 10 moves each digit 1 place to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 10 makes every digit 10 times smaller.
- Move every digit 1 column to the right. Each digit slides one column to the right, to a column that is worth 10 times less.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.5 ÷ 10 = 0.5
Check. Go the other way: 0.5 × 10 = 5. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 10 moves each digit 1 place to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 10 makes every digit 10 times smaller.
- Move every digit 1 column to the right. Each digit slides one column to the right, to a column that is worth 10 times less.
- Write the answer. Put the decimal point after the ones.34 ÷ 10 = 3.4
Check. Go the other way: 3.4 × 10 = 34. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 100 moves each digit 2 places to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 100 makes every digit 100 times smaller.
- Move every digit 2 columns to the right. Each digit slides two columns to the right, because dividing by 100 is dividing by 10 twice.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.7 ÷ 100 = 0.07
Check. Go the other way: 0.07 × 100 = 7. ✓
Watch out. The digits move, not the decimal point. And 5 ÷ 100 is 0.05: you need a 0 in the tenths column as well as the ones column.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 100 moves each digit 2 places to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 100 makes every digit 100 times smaller.
- Move every digit 2 columns to the right. Each digit slides two columns to the right, because dividing by 100 is dividing by 10 twice.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.26 ÷ 100 = 0.26
Check. Go the other way: 0.26 × 100 = 26. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Use the opposite operation. The opposite of dividing is multiplying.
- Think about the opposite operation. The opposite of dividing by 10 is multiplying by 10.? = 7 × 10
- Move every digit 1 column to the left. Multiplying makes each digit bigger, so the digits move left.7 × 10 = 70
- Write the answer. 70 ÷ 10 = 7
Check. Check: 70 ÷ 10 = 7. ✓
Watch out. Dividing moves digits right. To undo it, move them left.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Use the opposite operation. The opposite of dividing is multiplying.
- Think about the opposite operation. The opposite of dividing by 100 is multiplying by 100.? = 0.9 × 100
- Move every digit 2 columns to the left. Multiplying makes each digit bigger, so the digits move left.0.9 × 100 = 90
- Write the answer. 90 ÷ 100 = 0.9
Check. Check: 90 ÷ 100 = 0.9. ✓
Watch out. Dividing moves digits right. To undo it, move them left.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Use the opposite operation. The opposite of dividing is multiplying.
- Think about the opposite operation. The opposite of dividing by 10 is multiplying by 10.? = 4.2 × 10
- Move every digit 1 column to the left. Multiplying makes each digit bigger, so the digits move left.4.2 × 10 = 42
- Write the answer. 42 ÷ 10 = 4.2
Check. Check: 42 ÷ 10 = 4.2. ✓
Watch out. Dividing moves digits right. To undo it, move them left.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Use the opposite operation. The opposite of dividing is multiplying.
- Think about the opposite operation. The opposite of dividing by 100 is multiplying by 100.? = 0.35 × 100
- Move every digit 2 columns to the left. Multiplying makes each digit bigger, so the digits move left.0.35 × 100 = 35
- Write the answer. 35 ÷ 100 = 0.35
Check. Check: 35 ÷ 100 = 0.35. ✓
Watch out. Dividing moves digits right. To undo it, move them left.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Count how many columns the digits moved to the right. One column is ÷ 10 and two columns is ÷ 100.
- Compare the two numbers. 8 became 0.8.8 → 0.8
- Count how many columns the digits moved. Each digit moved to the right.The digits moved 1 column to the right.
- Decide what we divided by. 1 column means ÷ 10. 2 columns means ÷ 100.10
Check. Check: 8 ÷ 10 = 0.8. ✓
Watch out. Compare where the digits are, not how long the number looks.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Count how many columns the digits moved to the right. One column is ÷ 10 and two columns is ÷ 100.
- Compare the two numbers. 63 became 0.63.63 → 0.63
- Count how many columns the digits moved. Each digit moved to the right.The digits moved 2 columns to the right.
- Decide what we divided by. 1 column means ÷ 10. 2 columns means ÷ 100.100
Check. Check: 63 ÷ 100 = 0.63. ✓
Watch out. Compare where the digits are, not how long the number looks.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Count how many columns the digits moved to the right. One column is ÷ 10 and two columns is ÷ 100.
- Compare the two numbers. 95 became 9.5.95 → 9.5
- Count how many columns the digits moved. Each digit moved to the right.The digits moved 1 column to the right.
- Decide what we divided by. 1 column means ÷ 10. 2 columns means ÷ 100.10
Check. Check: 95 ÷ 10 = 9.5. ✓
Watch out. Compare where the digits are, not how long the number looks.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Count how many columns the digits moved to the right. One column is ÷ 10 and two columns is ÷ 100.
- Compare the two numbers. 4 became 0.04.4 → 0.04
- Count how many columns the digits moved. Each digit moved to the right.The digits moved 2 columns to the right.
- Decide what we divided by. 1 column means ÷ 10. 2 columns means ÷ 100.100
Check. Check: 4 ÷ 100 = 0.04. ✓
Watch out. Compare where the digits are, not how long the number looks.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Find the rule: divide by 10 each time. Move the digits one column to the right every step.
- Look at two numbers next to each other. Find what happens each time.600 → 60: the number is divided by 10 (every digit moves 1 column right).
- Keep dividing by 10. Each digit moves one more column to the right each time.600, 60, 6, 0.6, 0.06
- Write the missing numbers. 6, 0.06
Check. Multiply the last number by 10 and see if you get the one before. ✓
Watch out. After 0.7 comes 0.07 (not 0.007 and not 0.70).
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Find the rule: divide by 10 each time. Move the digits one column to the right every step.
- Look at two numbers next to each other. Find what happens each time.90 → 9: the number is divided by 10 (every digit moves 1 column right).
- Keep dividing by 10. Each digit moves one more column to the right each time.90, 9, 0.9, 0.09
- Write the missing numbers. 0.9, 0.09
Check. Multiply the last number by 10 and see if you get the one before. ✓
Watch out. After 0.7 comes 0.07 (not 0.007 and not 0.70).
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Find the rule: divide by 10 each time. Move the digits one column to the right every step.
- Look at two numbers next to each other. Find what happens each time.70 → 7: the number is divided by 10 (every digit moves 1 column right).
- Keep dividing by 10. Each digit moves one more column to the right each time.70, 7, 0.7, 0.07
- Write the missing numbers. 7, 0.07
Check. Multiply the last number by 10 and see if you get the one before. ✓
Watch out. After 0.7 comes 0.07 (not 0.007 and not 0.70).
Key words. Convert means change from one unit to another. 1 m = 100 cm. 1 cm = 10 mm.
Method. There are 100 cm in 1 m. Divide by 100 to change cm into m.
- Find how many of the small unit make one of the big unit. We need this to change units.1 m = 100 cm
- Choose the operation. We are changing cm into m. A m is bigger, so we need fewer of them: divide by 100.300 ÷ 100
- Move the digits 2 columns to the right. Dividing by 100 makes each digit 100 times smaller.300 ÷ 100 = 3
- Write the answer with the unit. 300 cm = 3 m
Check. Go back: 3 × 100 = 300. ✓
Watch out. Fewer m than cm: the number should get smaller. If it does not, you used the wrong operation.
Key words. Convert means change from one unit to another. 1 m = 100 cm. 1 cm = 10 mm.
Method. There are 100 cm in 1 m. Divide by 100 to change cm into m.
- Find how many of the small unit make one of the big unit. We need this to change units.1 m = 100 cm
- Choose the operation. We are changing cm into m. A m is bigger, so we need fewer of them: divide by 100.450 ÷ 100
- Move the digits 2 columns to the right. Dividing by 100 makes each digit 100 times smaller.450 ÷ 100 = 4.5
- Write the answer with the unit. 450 cm = 4.5 m
Check. Go back: 4.5 × 100 = 450. ✓
Watch out. Fewer m than cm: the number should get smaller. If it does not, you used the wrong operation.
Key words. Convert means change from one unit to another. 1 m = 100 cm. 1 cm = 10 mm.
Method. There are 10 mm in 1 cm. Divide by 10 to change mm into cm.
- Find how many of the small unit make one of the big unit. We need this to change units.1 cm = 10 mm
- Choose the operation. We are changing mm into cm. A cm is bigger, so we need fewer of them: divide by 10.36 ÷ 10
- Move the digits 1 column to the right. Dividing by 10 makes each digit 10 times smaller.36 ÷ 10 = 3.6
- Write the answer with the unit. 36 mm = 3.6 cm
Check. Go back: 3.6 × 10 = 36. ✓
Watch out. Fewer cm than mm: the number should get smaller. If it does not, you used the wrong operation.
Key words. Convert means change from one unit to another. 1 m = 100 cm. 1 cm = 10 mm.
Method. There are 10 mm in 1 cm. Divide by 10 to change mm into cm.
- Find how many of the small unit make one of the big unit. We need this to change units.1 cm = 10 mm
- Choose the operation. We are changing mm into cm. A cm is bigger, so we need fewer of them: divide by 10.7 ÷ 10
- Move the digits 1 column to the right. Dividing by 10 makes each digit 10 times smaller.7 ÷ 10 = 0.7
- Write the answer with the unit. 7 mm = 0.7 cm
Check. Go back: 0.7 × 10 = 7. ✓
Watch out. Fewer cm than mm: the number should get smaller. If it does not, you used the wrong operation.
Key words. Convert means change from one unit to another. 1 m = 100 cm. 1 cm = 10 mm.
Method. There are 100 cm in 1 m. Multiply by 100 to change m into cm.
- Find how many of the small unit make one of the big unit. We need this to change units.1 m = 100 cm
- Choose the operation. We are changing m into cm. A cm is smaller, so we need more of them: multiply by 100.3.5 × 100
- Move the digits 2 columns to the left. Multiplying by 100 makes each digit 100 times bigger.3.5 × 100 = 350
- Write the answer with the unit. 3.5 m = 350 cm
Check. Go back: 350 ÷ 100 = 3.5. ✓
Watch out. More cm than m: the number should get bigger. If it does not, you used the wrong operation.
Key words. Convert means change from one unit to another. 1 m = 100 cm. 1 cm = 10 mm.
Method. There are 100 cm in 1 m. Multiply by 100 to change m into cm.
- Find how many of the small unit make one of the big unit. We need this to change units.1 m = 100 cm
- Choose the operation. We are changing m into cm. A cm is smaller, so we need more of them: multiply by 100.0.72 × 100
- Move the digits 2 columns to the left. Multiplying by 100 makes each digit 100 times bigger.0.72 × 100 = 72
- Write the answer with the unit. 0.72 m = 72 cm
Check. Go back: 72 ÷ 100 = 0.72. ✓
Watch out. More cm than m: the number should get bigger. If it does not, you used the wrong operation.
Key words. Convert means change from one unit to another. 1 m = 100 cm. 1 cm = 10 mm.
Method. There are 100 cm in 1 m. Multiply by 100 to change m into cm.
- Find how many of the small unit make one of the big unit. We need this to change units.1 m = 100 cm
- Choose the operation. We are changing m into cm. A cm is smaller, so we need more of them: multiply by 100.6 × 100
- Move the digits 2 columns to the left. Multiplying by 100 makes each digit 100 times bigger.6 × 100 = 600
- Write the answer with the unit. 6 m = 600 cm
Check. Go back: 600 ÷ 100 = 6. ✓
Watch out. More cm than m: the number should get bigger. If it does not, you used the wrong operation.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 10 moves each digit 1 place to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 10 makes every digit 10 times smaller.
- Move every digit 1 column to the right. Each digit slides one column to the right, to a column that is worth 10 times less.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.6 ÷ 10 = 0.6 m
Check. Go the other way: 0.6 × 10 = 6. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 100 moves each digit 2 places to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 100 makes every digit 100 times smaller.
- Move every digit 2 columns to the right. Each digit slides two columns to the right, because dividing by 100 is dividing by 10 twice.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.6 ÷ 100 = 0.06 m
Check. Go the other way: 0.06 × 100 = 6. ✓
Watch out. The digits move, not the decimal point. And 5 ÷ 100 is 0.05: you need a 0 in the tenths column as well as the ones column.
Key words. Convert means change from one unit to another. 1 m = 100 cm. 1 cm = 10 mm.
Method. There are 100 cm in 1 m. Divide by 100 to change cm into m.
- Find how many of the small unit make one of the big unit. We need this to change units.1 m = 100 cm
- Choose the operation. We are changing cm into m. A m is bigger, so we need fewer of them: divide by 100.75 ÷ 100
- Move the digits 2 columns to the right. Dividing by 100 makes each digit 100 times smaller.75 ÷ 100 = 0.75
- Write the answer with the unit. 75 cm = 0.75 m
Check. Go back: 0.75 × 100 = 75. ✓
Watch out. Fewer m than cm: the number should get smaller. If it does not, you used the wrong operation.
Key words. Convert means change from one unit to another. 1 m = 100 cm. 1 cm = 10 mm.
Method. There are 100 cm in 1 m. Divide by 100 to change cm into m.
- Find how many of the small unit make one of the big unit. We need this to change units.1 m = 100 cm
- Choose the operation. We are changing cm into m. A m is bigger, so we need fewer of them: divide by 100.68 ÷ 100
- Move the digits 2 columns to the right. Dividing by 100 makes each digit 100 times smaller.68 ÷ 100 = 0.68
- Write the answer with the unit. 68 cm = 0.68 m
Check. Go back: 0.68 × 100 = 68. ✓
Watch out. Fewer m than cm: the number should get smaller. If it does not, you used the wrong operation.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Work out 5 ÷ 10 yourself using the place-value chart, and compare with Jack’s answer.
- Look at Jack’s answer. Jack says 5 ÷ 10 = 0.05.0.05 is 5 hundredths. That is what we get from 5 ÷ 100.
- Work out 5 ÷ 10 correctly. Divide by 10: move the 5 one column to the right, into the tenths column.
- Write the answer. 5 ones becomes 5 tenths.5 ÷ 10 = 0.5
Check. 0.5 × 10 = 5. ✓
Watch out. One column for ÷ 10, two columns for ÷ 100.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Try the biggest two-digit number, 99, and a few others. Divide by 100 each time.
- Try 99 ÷ 100. This is the biggest two-digit number.99 ÷ 100 = 0.99, which is less than 1.
- Try some other two-digit numbers. Smaller numbers give smaller answers.50 ÷ 100 = 0.5 10 ÷ 100 = 0.1 25 ÷ 100 = 0.25
- Explain. A two-digit number is less than 100. If we divide a number smaller than 100 by 100, we get less than 1.Always
Check. 100 ÷ 100 = 1, and every two-digit number is less than 100. ✓
Watch out. “Always” means every case. 100 itself has three digits.
A 4 ÷ 10 B 40 ÷ 100 C 40 ÷ 10 D 4 ÷ 100 E 400 ÷ 100
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Work out each division. Look for the answers that equal 0.4.
- Work out each division. Move the digits to the right.A: 4 ÷ 10 = 0.4 ✓
B: 40 ÷ 100 = 0.4 ✓
C: 40 ÷ 10 = 4
D: 4 ÷ 100 = 0.04
E: 400 ÷ 100 = 4 - Choose the two that make 0.4. A and B
Check. 0.4 × 10 = 4 and 0.4 × 100 = 40. ✓
Watch out. Check each one. Do not guess from the digits.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Try it with 50. Divide by 10, then divide that answer by 10 again, and compare with dividing 50 by 100.
- Divide 50 by 10. Move the digits one column to the right.50 ÷ 10 = 5
- Divide the answer by 10 again. Move the digits one more column to the right.5 ÷ 10 = 0.5
- Compare with dividing 50 by 100. Move the digits two columns to the right.50 ÷ 100 = 0.5
- Decide. Dividing by 10 twice has the same effect as dividing by 100 once.100
Check. 10 × 10 = 100. ✓
Watch out. Two moves of one column make a move of two columns.
Comparing, ordering and rounding decimals
Printable: Worksheet (PDF) · Answers (PDF) · Open this lesson on its own page
To compare two decimals, write them in a place-value table with the decimal points lined up. Then compare the digits from the left. The first column where the digits are different tells you which number is bigger.
| ones | tenths | hundredths | ||
|---|---|---|---|---|
| 5.34 | 5 | . | 3 | 4 |
| 5.39 | 5 | . | 3 | 9 |
| ones | tenths | ||
|---|---|---|---|
| 4.8 | 4 | . | 8 |
| 4.3 | 4 | . | 3 |
A picture helps. Look at 0.45 and 0.54. The first has 4 full rows and 5 squares. The second has 5 full rows and 4 squares. 5 tenths is more than 4 tenths, so 0.54 is bigger.
0.45
0.54
Ordering means putting numbers in a list. Compare the ones, then the tenths, then the hundredths. For example, to order 0.82, 0.28, 0.88 and 0.08 from smallest to biggest: all have 0 ones. The tenths digits are 8, 2, 8 and 0. So 0.08 is the smallest, then 0.28. The other two both have 8 tenths, so compare hundredths: 0.82 < 0.88. The order is 0.08, 0.28, 0.82, 0.88.
Rounding to the nearest whole number. Look at 3.4. It is between 3 and 4. On a number line, 3.4 is closer to 3.
The halfway point between 3 and 4 is 3.5. Numbers below 3.5 are closer to 3. Numbers from 3.5 up are closer to 4 (halfway, 3.5, rounds up).
The quick rule: look at the tenths digit (the first digit after the point). If it is 5 or more, round up to the next whole number. If it is 4 or less, round down (keep the whole number).
Key words. To compare is to say which is bigger. To order is to put in a list. To round is to change to a nearby number that is easier to use.
Key ideas
- Line up the decimal points and compare the digits from the left.
- The first column where the digits are different decides which number is bigger.
- Order: compare ones, then tenths, then hundredths. List all the numbers.
- Rounding to the nearest whole number: look at the tenths digit.
- 5 or more: round up. 4 or less: round down.
- Halfway (like 3.5) rounds up.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths 4.8 4 . 8 4.3 4 . 3 - Compare the digits from the left. The first column where the digits are different decides.ones: 4 and 4 are the same, so look at the next column.
tenths: 8 and 3 are different. 8 > 3, so 4.8 is bigger. - Write the answer. < means “is less than” and > means “is greater than”.4.8 > 4.3
Check. Picture a number line: 4.3 is to the left of 4.8. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths hundredths 5.34 5 . 3 4 5.39 5 . 3 9 - Compare the digits from the left. The first column where the digits are different decides.ones: 5 and 5 are the same, so look at the next column.
tenths: 3 and 3 are the same, so look at the next column.
hundredths: 4 and 9 are different. 4 < 9, so 5.34 is smaller. - Write the answer. < means “is less than” and > means “is greater than”.5.34 < 5.39
Check. Picture a number line: 5.34 is to the left of 5.39. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths hundredths 2.45 2 . 4 5 3.12 3 . 1 2 - Compare the digits from the left. The first column where the digits are different decides.ones: 2 and 3 are different. 2 < 3, so 2.45 is smaller.
- Write the answer. < means “is less than” and > means “is greater than”.2.45 < 3.12
Check. Picture a number line: 2.45 is to the left of 3.12. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To order numbers is to put them in a list. Ascending means smallest first. Descending means biggest first.
Method. Write the numbers in a place-value table and compare the digits column by column, starting from the left. Then list them smallest first.
- Write the numbers in a place-value table. Line up the decimal points.
ones tenths hundredths 0.82 0 . 8 2 0.28 0 . 2 8 0.88 0 . 8 8 0.08 0 . 0 8 - Compare the columns from the left. Where the digits are the same, look at the next column to the right.Ones: 0.82 has 0, 0.28 has 0, 0.88 has 0, 0.08 has 0. All the same, so look at the next column.
Tenths: 0.82 has 8, 0.28 has 2, 0.88 has 8, 0.08 has 0. Smallest to biggest: 0, 2, 8.
Hundredths: 0.82 has 2, 0.88 has 8. Smallest to biggest: 2, 8. - Write them smallest first. Write the ORIGINAL numbers and check that you have used every one.0.08, 0.28, 0.82, 0.88
Check. Count them: 4 numbers in the question and 4 in the answer. ✓
Watch out. Do not forget a number. Tick each one off as you write it.
Key words. To order numbers is to put them in a list. Ascending means smallest first. Descending means biggest first.
Method. Write the numbers in a place-value table and compare the digits column by column, starting from the left. Then list them biggest first.
- Write the numbers in a place-value table. Line up the decimal points.
ones tenths 3.6 3 . 6 3.1 3 . 1 2.9 2 . 9 3.0 3 . 0 - Compare the columns from the left. Where the digits are the same, look at the next column to the right.Ones: 3.6 has 3, 3.1 has 3, 2.9 has 2, 3.0 has 3. Smallest to biggest: 2, 3.
Tenths: 3.6 has 6, 3.1 has 1, 3.0 has 0. Smallest to biggest: 0, 1, 6. - Write them biggest first. Write the ORIGINAL numbers and check that you have used every one.3.6, 3.1, 3.0, 2.9
Check. Count them: 4 numbers in the question and 4 in the answer. ✓
Watch out. Do not forget a number. Tick each one off as you write it.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 4.3 is between. Rounding to the nearest whole number means choosing the closest whole number.4 < 4.3 < 5
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 3.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)3 is 4 or less, so round down.
- Look at the number line. The orange dot is 4.3. The green ring is the nearest whole number.
- Write the answer. 4.3 ≈ 4 (to the nearest whole number)
Check. Distances: 4.3 − 4 = 0.3 and 5 − 4.3 = 0.7. 4 is the nearer whole number. ✓
Watch out. Only the tenths digit decides. A number like 3.49 rounds down, even though 9 is big: look at the first digit after the point only.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 7.6 is between. Rounding to the nearest whole number means choosing the closest whole number.7 < 7.6 < 8
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 6.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)6 is 5 or more, so round up.
- Look at the number line. The orange dot is 7.6. The green ring is the nearest whole number.
- Write the answer. 7.6 ≈ 8 (to the nearest whole number)
Check. Distances: 7.6 − 7 = 0.6 and 8 − 7.6 = 0.4. 8 is the nearer whole number. ✓
Watch out. Only the tenths digit decides. A number like 3.49 rounds down, even though 9 is big: look at the first digit after the point only.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 5.5 is between. Rounding to the nearest whole number means choosing the closest whole number.5 < 5.5 < 6
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 5.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)5 is 5 or more, so round up.
- Look at the number line. The orange dot is 5.5. The green ring is the nearest whole number.
- Write the answer. 5.5 ≈ 6 (to the nearest whole number)
Check. Distances: 5.5 − 5 = 0.5 and 6 − 5.5 = 0.5. 6 is the one we choose when exactly halfway. ✓
Watch out. Exactly halfway (like 6.5) always rounds UP.
Watch out
More digits does not mean a bigger number. 0.45 is smaller than 0.5 even though 45 is bigger than 5. Write 0.5 as 0.50 and compare 45 hundredths with 50 hundredths. And when you round, only look at the tenths digit: 4.49 would round down because the tenths digit is 4.Exercise 6E Comparing, ordering and rounding decimals
Non-calculator0.4
0.7
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths 0.4 0 . 4 0.7 0 . 7 - Compare the digits from the left. The first column where the digits are different decides.ones: 0 and 0 are the same, so look at the next column.
tenths: 4 and 7 are different. 4 < 7, so 0.4 is smaller. - Write the answer. < means “is less than” and > means “is greater than”.0.4 < 0.7
Check. Picture a number line: 0.4 is to the left of 0.7. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
0.35
0.53
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths hundredths 0.35 0 . 3 5 0.53 0 . 5 3 - Compare the digits from the left. The first column where the digits are different decides.ones: 0 and 0 are the same, so look at the next column.
tenths: 3 and 5 are different. 3 < 5, so 0.35 is smaller. - Write the answer. < means “is less than” and > means “is greater than”.0.35 < 0.53
Check. Picture a number line: 0.35 is to the left of 0.53. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
0.8
0.08
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Give both numbers the same number of decimal places. Adding a 0 on the end of a decimal does not change its value (0.5 = 0.50).0.8 = 0.80 and 0.08 = 0.08
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths hundredths 0.80 0 . 8 0 0.08 0 . 0 8 - Compare the digits from the left. The first column where the digits are different decides.ones: 0 and 0 are the same, so look at the next column.
tenths: 8 and 0 are different. 8 > 0, so 0.80 is bigger. - Write the answer. < means “is less than” and > means “is greater than”.0.8 > 0.08
Check. Picture a number line: 0.08 is to the left of 0.8. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths 0.3 0 . 3 0.8 0 . 8 - Compare the digits from the left. The first column where the digits are different decides.ones: 0 and 0 are the same, so look at the next column.
tenths: 3 and 8 are different. 3 < 8, so 0.3 is smaller. - Write the answer. < means “is less than” and > means “is greater than”.0.3 < 0.8
Check. Picture a number line: 0.3 is to the left of 0.8. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths 2.5 2 . 5 2.1 2 . 1 - Compare the digits from the left. The first column where the digits are different decides.ones: 2 and 2 are the same, so look at the next column.
tenths: 5 and 1 are different. 5 > 1, so 2.5 is bigger. - Write the answer. < means “is less than” and > means “is greater than”.2.5 > 2.1
Check. Picture a number line: 2.1 is to the left of 2.5. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths 4.0 4 . 0 3.9 3 . 9 - Compare the digits from the left. The first column where the digits are different decides.ones: 4 and 3 are different. 4 > 3, so 4.0 is bigger.
- Write the answer. < means “is less than” and > means “is greater than”.4.0 > 3.9
Check. Picture a number line: 3.9 is to the left of 4.0. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths 6.7 6 . 7 6.9 6 . 9 - Compare the digits from the left. The first column where the digits are different decides.ones: 6 and 6 are the same, so look at the next column.
tenths: 7 and 9 are different. 7 < 9, so 6.7 is smaller. - Write the answer. < means “is less than” and > means “is greater than”.6.7 < 6.9
Check. Picture a number line: 6.7 is to the left of 6.9. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths 9.1 9 . 1 8.9 8 . 9 - Compare the digits from the left. The first column where the digits are different decides.ones: 9 and 8 are different. 9 > 8, so 9.1 is bigger.
- Write the answer. < means “is less than” and > means “is greater than”.9.1 > 8.9
Check. Picture a number line: 8.9 is to the left of 9.1. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths 3.3 3 . 3 3.3 3 . 3 - Compare the digits from the left. The first column where the digits are different decides.ones: 3 and 3 are the same, so look at the next column.
tenths: 3 and 3 are the same. Every column is the same, so the numbers are equal. - Write the answer. < means “is less than” and > means “is greater than”.3.3 = 3.3
Check. Both numbers are worth the same. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths hundredths 0.34 0 . 3 4 0.43 0 . 4 3 - Compare the digits from the left. The first column where the digits are different decides.ones: 0 and 0 are the same, so look at the next column.
tenths: 3 and 4 are different. 3 < 4, so 0.34 is smaller. - Write the answer. < means “is less than” and > means “is greater than”.0.34 < 0.43
Check. Picture a number line: 0.34 is to the left of 0.43. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths hundredths 5.62 5 . 6 2 5.26 5 . 2 6 - Compare the digits from the left. The first column where the digits are different decides.ones: 5 and 5 are the same, so look at the next column.
tenths: 6 and 2 are different. 6 > 2, so 5.62 is bigger. - Write the answer. < means “is less than” and > means “is greater than”.5.62 > 5.26
Check. Picture a number line: 5.26 is to the left of 5.62. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths hundredths 1.07 1 . 0 7 1.70 1 . 7 0 - Compare the digits from the left. The first column where the digits are different decides.ones: 1 and 1 are the same, so look at the next column.
tenths: 0 and 7 are different. 0 < 7, so 1.07 is smaller. - Write the answer. < means “is less than” and > means “is greater than”.1.07 < 1.70
Check. Picture a number line: 1.07 is to the left of 1.70. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths hundredths 3.45 3 . 4 5 3.45 3 . 4 5 - Compare the digits from the left. The first column where the digits are different decides.ones: 3 and 3 are the same, so look at the next column.
tenths: 4 and 4 are the same, so look at the next column.
hundredths: 5 and 5 are the same. Every column is the same, so the numbers are equal. - Write the answer. < means “is less than” and > means “is greater than”.3.45 = 3.45
Check. Both numbers are worth the same. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths hundredths 0.58 0 . 5 8 0.59 0 . 5 9 - Compare the digits from the left. The first column where the digits are different decides.ones: 0 and 0 are the same, so look at the next column.
tenths: 5 and 5 are the same, so look at the next column.
hundredths: 8 and 9 are different. 8 < 9, so 0.58 is smaller. - Write the answer. < means “is less than” and > means “is greater than”.0.58 < 0.59
Check. Picture a number line: 0.58 is to the left of 0.59. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Write the numbers in a place-value table. Compare the digits from the left. The first column where they are different decides which number is bigger.
- Write both numbers in a place-value table. Line up the decimal points so each digit is above a digit of the same value.
ones tenths hundredths 7.91 7 . 9 1 7.19 7 . 1 9 - Compare the digits from the left. The first column where the digits are different decides.ones: 7 and 7 are the same, so look at the next column.
tenths: 9 and 1 are different. 9 > 1, so 7.91 is bigger. - Write the answer. < means “is less than” and > means “is greater than”.7.91 > 7.19
Check. Picture a number line: 7.19 is to the left of 7.91. ✓
Watch out. Start at the LEFT, with the biggest column. And do not count the digits: 0.45 is smaller than 0.5, even though 45 is bigger than 5.
Key words. To order numbers is to put them in a list. Ascending means smallest first. Descending means biggest first.
Method. Write the numbers in a place-value table and compare the digits column by column, starting from the left. Then list them smallest first.
- Write the numbers in a place-value table. Line up the decimal points.
ones tenths 0.6 0 . 6 0.2 0 . 2 0.9 0 . 9 0.4 0 . 4 - Compare the columns from the left. Where the digits are the same, look at the next column to the right.Ones: 0.6 has 0, 0.2 has 0, 0.9 has 0, 0.4 has 0. All the same, so look at the next column.
Tenths: 0.6 has 6, 0.2 has 2, 0.9 has 9, 0.4 has 4. Smallest to biggest: 2, 4, 6, 9. - Write them smallest first. Write the ORIGINAL numbers and check that you have used every one.0.2, 0.4, 0.6, 0.9
Check. Count them: 4 numbers in the question and 4 in the answer. ✓
Watch out. Do not forget a number. Tick each one off as you write it.
Key words. To order numbers is to put them in a list. Ascending means smallest first. Descending means biggest first.
Method. Write the numbers in a place-value table and compare the digits column by column, starting from the left. Then list them smallest first.
- Write the numbers in a place-value table. Line up the decimal points.
ones tenths 3.7 3 . 7 3.1 3 . 1 2.8 2 . 8 3.0 3 . 0 - Compare the columns from the left. Where the digits are the same, look at the next column to the right.Ones: 3.7 has 3, 3.1 has 3, 2.8 has 2, 3.0 has 3. Smallest to biggest: 2, 3.
Tenths: 3.7 has 7, 3.1 has 1, 3.0 has 0. Smallest to biggest: 0, 1, 7. - Write them smallest first. Write the ORIGINAL numbers and check that you have used every one.2.8, 3.0, 3.1, 3.7
Check. Count them: 4 numbers in the question and 4 in the answer. ✓
Watch out. Do not forget a number. Tick each one off as you write it.
Key words. To order numbers is to put them in a list. Ascending means smallest first. Descending means biggest first.
Method. Write the numbers in a place-value table and compare the digits column by column, starting from the left. Then list them smallest first.
- Write the numbers in a place-value table. Line up the decimal points.
ones tenths hundredths 0.45 0 . 4 5 0.54 0 . 5 4 0.04 0 . 0 4 0.40 0 . 4 0 - Compare the columns from the left. Where the digits are the same, look at the next column to the right.Ones: 0.45 has 0, 0.54 has 0, 0.04 has 0, 0.40 has 0. All the same, so look at the next column.
Tenths: 0.45 has 4, 0.54 has 5, 0.04 has 0, 0.40 has 4. Smallest to biggest: 0, 4, 5.
Hundredths: 0.45 has 5, 0.40 has 0. Smallest to biggest: 0, 5. - Write them smallest first. Write the ORIGINAL numbers and check that you have used every one.0.04, 0.40, 0.45, 0.54
Check. Count them: 4 numbers in the question and 4 in the answer. ✓
Watch out. Do not forget a number. Tick each one off as you write it.
Key words. To order numbers is to put them in a list. Ascending means smallest first. Descending means biggest first.
Method. Write the numbers in a place-value table and compare the digits column by column, starting from the left. Then list them biggest first.
- Write the numbers in a place-value table. Line up the decimal points.
ones tenths 1.5 1 . 5 5.1 5 . 1 1.1 1 . 1 5.5 5 . 5 - Compare the columns from the left. Where the digits are the same, look at the next column to the right.Ones: 1.5 has 1, 5.1 has 5, 1.1 has 1, 5.5 has 5. Smallest to biggest: 1, 5.
Tenths: 1.5 has 5, 1.1 has 1. Smallest to biggest: 1, 5.
Tenths: 5.1 has 1, 5.5 has 5. Smallest to biggest: 1, 5. - Write them biggest first. Write the ORIGINAL numbers and check that you have used every one.5.5, 5.1, 1.5, 1.1
Check. Count them: 4 numbers in the question and 4 in the answer. ✓
Watch out. Do not forget a number. Tick each one off as you write it.
Key words. To order numbers is to put them in a list. Ascending means smallest first. Descending means biggest first.
Method. Write the numbers in a place-value table and compare the digits column by column, starting from the left. Then list them biggest first.
- Write the numbers in a place-value table. Line up the decimal points.
ones tenths hundredths 0.72 0 . 7 2 0.27 0 . 2 7 0.77 0 . 7 7 0.07 0 . 0 7 - Compare the columns from the left. Where the digits are the same, look at the next column to the right.Ones: 0.72 has 0, 0.27 has 0, 0.77 has 0, 0.07 has 0. All the same, so look at the next column.
Tenths: 0.72 has 7, 0.27 has 2, 0.77 has 7, 0.07 has 0. Smallest to biggest: 0, 2, 7.
Hundredths: 0.72 has 2, 0.77 has 7. Smallest to biggest: 2, 7. - Write them biggest first. Write the ORIGINAL numbers and check that you have used every one.0.77, 0.72, 0.27, 0.07
Check. Count them: 4 numbers in the question and 4 in the answer. ✓
Watch out. Do not forget a number. Tick each one off as you write it.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Work out what one gap is worth. Then count on from the left end.
- Find the two numbers at the ends and count the gaps. All the gaps on a number line are the same size.The line goes from 5 to 6 in 10 equal gaps.
- Work out what one gap is worth. Share the distance between the ends equally.1 ÷ 10 = 0.1
- Count the gaps from the left end to the point. Count the gaps, not the tick marks.The point is 7 gaps after 5.
- Work out the number. Start at the left end and add the gaps.5 + 7 × 0.1 = 5 + 0.7 = 5.7
Check. Count back from 6: 3 gaps back is 6 − 0.3 = 5.7. ✓
Watch out. Do not just read the nearest number on the line. Count the small gaps to find the exact value.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Work out what one gap is worth. Then count on from the left end.
- Find the two numbers at the ends and count the gaps. All the gaps on a number line are the same size.The line goes from 5 to 6 in 10 equal gaps.
- Work out what one gap is worth. Share the distance between the ends equally.1 ÷ 10 = 0.1
- Count the gaps from the left end to the point. Count the gaps, not the tick marks.The point is 2 gaps after 5.
- Work out the number. Start at the left end and add the gaps.5 + 2 × 0.1 = 5 + 0.2 = 5.2
Check. Count back from 6: 8 gaps back is 6 − 0.8 = 5.2. ✓
Watch out. Do not just read the nearest number on the line. Count the small gaps to find the exact value.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Work out what one gap is worth. Then count on from the left end.
- Find the two numbers at the ends and count the gaps. All the gaps on a number line are the same size.The line goes from 5 to 6 in 10 equal gaps.
- Work out what one gap is worth. Share the distance between the ends equally.1 ÷ 10 = 0.1
- Count the gaps from the left end to the point. Count the gaps, not the tick marks.The point is 9 gaps after 5.
- Work out the number. Start at the left end and add the gaps.5 + 9 × 0.1 = 5 + 0.9 = 5.9
Check. Count back from 6: 1 gap back is 6 − 0.1 = 5.9. ✓
Watch out. Do not just read the nearest number on the line. Count the small gaps to find the exact value.
Key words. To order numbers is to put them in a list. Ascending means smallest first. Descending means biggest first.
Method. Write the numbers in a place-value table and compare the digits column by column, starting from the left. Then list them smallest first.
- Write the numbers in a place-value table. Line up the decimal points.
ones tenths 5.7 5 . 7 5.2 5 . 2 5.9 5 . 9 - Compare the columns from the left. Where the digits are the same, look at the next column to the right.Ones: 5.7 has 5, 5.2 has 5, 5.9 has 5. All the same, so look at the next column.
Tenths: 5.7 has 7, 5.2 has 2, 5.9 has 9. Smallest to biggest: 2, 7, 9. - Write them smallest first. Write the ORIGINAL numbers and check that you have used every one.5.2, 5.7, 5.9
Check. Count them: 3 numbers in the question and 3 in the answer. ✓
Watch out. Do not forget a number. Tick each one off as you write it.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 3.4 is between. Rounding to the nearest whole number means choosing the closest whole number.3 < 3.4 < 4
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 4.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)4 is 4 or less, so round down.
- Write the answer. 3.4 ≈ 3 (to the nearest whole number)
Check. Distances: 3.4 − 3 = 0.4 and 4 − 3.4 = 0.6. 3 is the nearer whole number. ✓
Watch out. Only the tenths digit decides. A number like 3.49 rounds down, even though 9 is big: look at the first digit after the point only.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 6.5 is between. Rounding to the nearest whole number means choosing the closest whole number.6 < 6.5 < 7
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 5.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)5 is 5 or more, so round up.
- Write the answer. 6.5 ≈ 7 (to the nearest whole number)
Check. Distances: 6.5 − 6 = 0.5 and 7 − 6.5 = 0.5. 7 is the one we choose when exactly halfway. ✓
Watch out. Exactly halfway (like 6.5) always rounds UP.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 8.9 is between. Rounding to the nearest whole number means choosing the closest whole number.8 < 8.9 < 9
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 9.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)9 is 5 or more, so round up.
- Write the answer. 8.9 ≈ 9 (to the nearest whole number)
Check. Distances: 8.9 − 8 = 0.9 and 9 − 8.9 = 0.1. 9 is the nearer whole number. ✓
Watch out. Only the tenths digit decides. A number like 3.49 rounds down, even though 9 is big: look at the first digit after the point only.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 12.1 is between. Rounding to the nearest whole number means choosing the closest whole number.12 < 12.1 < 13
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 1.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)1 is 4 or less, so round down.
- Write the answer. 12.1 ≈ 12 (to the nearest whole number)
Check. Distances: 12.1 − 12 = 0.1 and 13 − 12.1 = 0.9. 12 is the nearer whole number. ✓
Watch out. Only the tenths digit decides. A number like 3.49 rounds down, even though 9 is big: look at the first digit after the point only.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 0.7 is between. Rounding to the nearest whole number means choosing the closest whole number.0 < 0.7 < 1
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 7.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)7 is 5 or more, so round up.
- Write the answer. 0.7 ≈ 1 (to the nearest whole number)
Check. Distances: 0.7 − 0 = 0.7 and 1 − 0.7 = 0.3. 1 is the nearer whole number. ✓
Watch out. Only the tenths digit decides. A number like 3.49 rounds down, even though 9 is big: look at the first digit after the point only.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 19.5 is between. Rounding to the nearest whole number means choosing the closest whole number.19 < 19.5 < 20
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 5.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)5 is 5 or more, so round up.
- Write the answer. 19.5 ≈ 20 (to the nearest whole number)
Check. Distances: 19.5 − 19 = 0.5 and 20 − 19.5 = 0.5. 20 is the one we choose when exactly halfway. ✓
Watch out. Exactly halfway (like 6.5) always rounds UP.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 2.3 is between. Rounding to the nearest whole number means choosing the closest whole number.2 < 2.3 < 3
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 3.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)3 is 4 or less, so round down.
- Write the answer. 2.3 ≈ 2 (to the nearest whole number)
Check. Distances: 2.3 − 2 = 0.3 and 3 − 2.3 = 0.7. 2 is the nearer whole number. ✓
Watch out. Only the tenths digit decides. A number like 3.49 rounds down, even though 9 is big: look at the first digit after the point only.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 6.8 is between. Rounding to the nearest whole number means choosing the closest whole number.6 < 6.8 < 7
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 8.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)8 is 5 or more, so round up.
- Write the answer. 6.8 ≈ 7 (to the nearest whole number)
Check. Distances: 6.8 − 6 = 0.8 and 7 − 6.8 = 0.2. 7 is the nearer whole number. ✓
Watch out. Only the tenths digit decides. A number like 3.49 rounds down, even though 9 is big: look at the first digit after the point only.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 9.5 is between. Rounding to the nearest whole number means choosing the closest whole number.9 < 9.5 < 10
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 5.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)5 is 5 or more, so round up.
- Write the answer. 9.5 ≈ 10 (to the nearest whole number)
Check. Distances: 9.5 − 9 = 0.5 and 10 − 9.5 = 0.5. 10 is the one we choose when exactly halfway. ✓
Watch out. Exactly halfway (like 6.5) always rounds UP.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Find the two whole numbers on either side. Then decide which one is closer.
- Find the whole numbers on each side. The whole part of 6.2 is 6, so it is between 6 and 7.6 < 6.2 < 7
- Look at the tenths digit. It tells us if we are past halfway.The tenths digit is 2.
- Choose the closer whole number. 5 or more is closer to the bigger whole number. 4 or less is closer to the smaller one.6.2 is closer to 6.
Check. Distances: 0.2 from 6 and 0.8 from 7. ✓
Watch out. Halfway rounds up.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Find the two whole numbers on either side. Then decide which one is closer.
- Find the whole numbers on each side. The whole part of 14.8 is 14, so it is between 14 and 15.14 < 14.8 < 15
- Look at the tenths digit. It tells us if we are past halfway.The tenths digit is 8.
- Choose the closer whole number. 5 or more is closer to the bigger whole number. 4 or less is closer to the smaller one.14.8 is closer to 15.
Check. Distances: 0.8 from 14 and 0.2 from 15. ✓
Watch out. Halfway rounds up.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Find the two whole numbers on either side. Then decide which one is closer.
- Find the whole numbers on each side. The whole part of 0.4 is 0, so it is between 0 and 1.0 < 0.4 < 1
- Look at the tenths digit. It tells us if we are past halfway.The tenths digit is 4.
- Choose the closer whole number. 5 or more is closer to the bigger whole number. 4 or less is closer to the smaller one.0.4 is closer to 0.
Check. Distances: 0.4 from 0 and 0.6 from 1. ✓
Watch out. Halfway rounds up.
Key words. To order numbers is to put them in a list. Ascending means smallest first. Descending means biggest first.
Method. Write the numbers in a place-value table and compare the digits column by column, starting from the left. Then list them biggest first.
- Write the numbers in a place-value table. Line up the decimal points.
ones tenths hundredths 2.35 2 . 3 5 2.53 2 . 5 3 2.30 2 . 3 0 - Compare the columns from the left. Where the digits are the same, look at the next column to the right.Ones: 2.35 has 2, 2.53 has 2, 2.30 has 2. All the same, so look at the next column.
Tenths: 2.35 has 3, 2.53 has 5, 2.30 has 3. Smallest to biggest: 3, 5.
Hundredths: 2.35 has 5, 2.30 has 0. Smallest to biggest: 0, 5. - Write them biggest first. Write the ORIGINAL numbers and check that you have used every one.2.53 m, 2.35 m, 2.30 m
Check. Count them: 3 numbers in the question and 3 in the answer. ✓
Watch out. Do not forget a number. Tick each one off as you write it.
Key words. To order numbers is to put them in a list. Ascending means smallest first. Descending means biggest first.
Method. Write the numbers in a place-value table and compare the digits column by column, starting from the left. Then list them smallest first.
- Write the numbers in a place-value table. Line up the decimal points.
ones tenths hundredths 2.35 2 . 3 5 2.53 2 . 5 3 2.30 2 . 3 0 - Compare the columns from the left. Where the digits are the same, look at the next column to the right.Ones: 2.35 has 2, 2.53 has 2, 2.30 has 2. All the same, so look at the next column.
Tenths: 2.35 has 3, 2.53 has 5, 2.30 has 3. Smallest to biggest: 3, 5.
Hundredths: 2.35 has 5, 2.30 has 0. Smallest to biggest: 0, 5. - Write them smallest first. Write the ORIGINAL numbers and check that you have used every one.2.30 m, 2.35 m, 2.53 m
Check. Count them: 3 numbers in the question and 3 in the answer. ✓
Watch out. Do not forget a number. Tick each one off as you write it.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 3.6 is between. Rounding to the nearest whole number means choosing the closest whole number.3 < 3.6 < 4
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 6.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)6 is 5 or more, so round up.
- Write the answer. 3.6 km ≈ 4 km (to the nearest whole number)
Check. Distances: 3.6 − 3 = 0.6 and 4 − 3.6 = 0.4. 4 is the nearer whole number. ✓
Watch out. Only the tenths digit decides. A number like 3.49 rounds down, even though 9 is big: look at the first digit after the point only.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 7.2 is between. Rounding to the nearest whole number means choosing the closest whole number.7 < 7.2 < 8
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 2.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)2 is 4 or less, so round down.
- Write the answer. 7.2 litres ≈ 7 litres (to the nearest whole number)
Check. Distances: 7.2 − 7 = 0.2 and 8 − 7.2 = 0.8. 7 is the nearer whole number. ✓
Watch out. Only the tenths digit decides. A number like 3.49 rounds down, even though 9 is big: look at the first digit after the point only.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 12.5 is between. Rounding to the nearest whole number means choosing the closest whole number.12 < 12.5 < 13
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 5.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)5 is 5 or more, so round up.
- Write the answer. 12.5 kg ≈ 13 kg (to the nearest whole number)
Check. Distances: 12.5 − 12 = 0.5 and 13 − 12.5 = 0.5. 13 is the one we choose when exactly halfway. ✓
Watch out. Exactly halfway (like 6.5) always rounds UP.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Compare the numbers column by column from the left, not as whole numbers. Give them the same number of decimal places first.
- Look at what Sam did. Sam compared 45 and 5 as if they were whole numbers.45 > 5, so Sam thinks 0.45 > 0.5
- Give both numbers the same number of decimal places. Adding a 0 on the end does not change the value.0.5 = 0.50
- Compare them in a place-value table. Look at the tenths first.
ones tenths hundredths 0.45 0 . 4 5 0.50 0 . 5 0 - Decide who is right. 0.45 < 0.5. Sam is wrong.
Check. On a number line, 0.5 = 0.50 is to the right of 0.45. ✓
Watch out. A decimal with more digits is not always bigger. Compare tenths first, then hundredths.
A 4.5 B 4.4 C 5.4 D 5.5
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Round each number to the nearest whole number. Look for the ones that round to 5.
- Round each number. Look at the tenths digit. 5 or more rounds up, 4 or less rounds down.A: 4.5 ≈ 5 ✓
B: 4.4 ≈ 4
C: 5.4 ≈ 5 ✓
D: 5.5 ≈ 6 - Choose the two that round to 5. A and C
Check. 4.5 is exactly halfway between 4 and 5 so it rounds up to 5. 5.5 rounds up to 6. ✓
Watch out. Halfway rounds up: 4.5 rounds to 5, and 5.5 rounds to 6.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. A number with one decimal place that rounds to 8 is between 7.5 and 8.4. Find the smallest and the biggest.
- Find the smallest. Numbers below 7.5 round down to 7. 7.5 is halfway, so it rounds up to 8.7.4 rounds to 7 but 7.5 rounds to 8.
- Find the biggest. Numbers from 8.5 up round to 9. 8.4 rounds down to 8.8.4 rounds to 8 but 8.5 rounds to 9, so the biggest is 8.4.
Check. 7.5 ≈ 8 and 8.4 ≈ 8, but 7.4 ≈ 7 and 8.5 ≈ 9. ✓
Watch out. Remember that halfway rounds up.
Money: pounds and pence
Printable: Worksheet (PDF) · Answers (PDF) · Open this lesson on its own page
In the UK we use pounds (£) and pence (p). 100 pence make 1 pound. These are the coins: 1p, 2p, 5p, 10p, 20p, 50p, £1 and £2.
And these are the notes: £5, £10, £20 and £50.
Writing money. Money is a decimal. The pounds go before the decimal point and the pence go after it, with two digits. Three pounds and five pence is £3.05, not £3.5 (that would be £3.50). Forty-five pence can be written as 45p or as £0.45. Never write both a £ sign and a p, like £0.45p.
Changing between pounds and pence. To change pounds to pence, multiply by 100: £2.07 = 207p. To change pence to pounds, divide by 100 (the digits move two places to the right, as in Section 6.4): 345p = £3.45. 7p = £0.07 (you need the 0 in the tenths place).
Adding up coins. Count how much each kind of coin is worth in pence, then add the amounts.
Comparing money. To compare amounts, change them to the same unit first. £3.40 and 304p: £3.40 = 340p. 340p is more than 304p, so £3.40 > 304p. Fewest coins. To make an amount with the fewest coins, take the biggest coin that fits, then the biggest coin that fits what is left, and so on.
Key words. Pence (p) are small amounts of money. Pounds (£) are bigger. Change to a different unit means to write the same amount in another unit.
Key ideas
- 100p = £1.
- Money has two digits after the decimal point: £3.05, £4.50.
- Pence to pounds: divide by 100. Pounds to pence: multiply by 100.
- 7p = £0.07, not £0.7. And £4.5 should be £4.50.
- Never write £ and p together.
- To compare money, change everything to pence first.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Count how much each kind of coin or note is worth in pence. Add the amounts. Then write the total in pounds and pence.
- Count each kind of note and coin. Group the same ones together. Change each group into pence.1 × £1 = 100p
1 × 50p = 50p
2 × 20p = 40p
1 × 10p = 10p
1 × 5p = 5p
1 × 2p = 2p - Add the groups, biggest first. Adding the big amounts first is easier. Keep a running total.100p
100p + 50p = 150p
150p + 40p = 190p
190p + 10p = 200p
200p + 5p = 205p
205p + 2p = 207p - Write the total. 100p = £1, so change to pounds and pence if it is 100p or more.207p = £2.07
Check. Add in a different order, smallest first: 2p + 5p + 10p + 20p + 20p + 50p + 100p = 207p. ✓
Watch out. Change everything to pence first. Do not add pounds and pence together as if they were the same.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Divide the pence by 100 to find the pounds. The pence left over go after the decimal point, with two digits.
- Remember: 100 pence make 1 pound. So we divide the pence by 100 to find the pounds.345 ÷ 100 = 3 remainder 45
- Write the pounds and the pence. 3 pounds and 45p.3 pounds and 45p
- Put them together with a decimal point. The pence always get two digits after the decimal point.£3.45
Check. Go back: £3.45 = 3 × 100 + 45 = 345p. ✓
Watch out. Money always has two digits after the decimal point.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Divide the pence by 100 to find the pounds. The pence left over go after the decimal point, with two digits.
- Remember: 100 pence make 1 pound. So we divide the pence by 100 to find the pounds.7 ÷ 100 = 0 remainder 7
- Write the pounds and the pence. The amount is less than 100p, so there are no whole pounds.0 pounds and 7p
- Put them together with a decimal point. The pence always get TWO digits: write a 0 in front if there is only one.£0.07 (the 0 holds the tens-of-pence place)
Check. Go back: £0.07 = 0 × 100 + 7 = 7p. ✓
Watch out. Do not write £0.7: money always has two digits after the point.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Multiply the pounds by 100 and add the pence.
- Remember: 1 pound is 100 pence. So we multiply the pounds by 100.2 × 100 = 200p
- Add the pence. The two digits after the decimal point are the pence.200p + 7p = 207p
- Write the answer with the unit p. Pence are written with a small p after the number.£2.07 = 207p
Check. Go back: 207p ÷ 100 = £2.07. ✓
Watch out. £2.07 is 207p, not 27p: if the pence are less than 10, put a 0 in: £2.07 = 207p.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change both amounts into the same unit (pence). Then compare the numbers.
- Change both amounts to pence. We can only compare money when it is in the same unit. To change pounds to pence, multiply by 100.£3.40 = 340p (£3 × 100 + 40 = 340)
304p = 304p - Compare the numbers of pence. The bigger number of pence is the bigger amount.340 > 304
- Write the answer. £3.40 > 304p
Check. Picture £3.40 and 304p as coins: more money in the first. ✓
Watch out. Do not compare 3.40 with 304 as they are. Change to the same unit first: 340p and 304p.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change every amount to pence. Put the numbers in order. Then write the amounts the way they were first written.
- Change every amount to pence. The amounts are in different units, so we change them all to pence (£1 = 100p).£1.20 = 120p
95p = 95p
£1.05 = 105p
110p = 110p - Put the numbers of pence in order. We want smallest first.95p, 105p, 110p, 120p
- Write the original amounts in that order. Use the way each amount was written in the question.95p, £1.05, 110p, £1.20
Check. Count them: 4 amounts in the question and 4 in the answer. ✓
Watch out. Do not mix up pence and pounds: 95p is less than £1.05 even though 95 is bigger than 1.05.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Start with the biggest coin that fits. Take it away, then do the same with what is left. Keep going until nothing is left.
- Take the biggest coin that is not more than 187p. Using the biggest coins each time gives the fewest coins.Take £1. 187p − 100p = 87p left
- Take the biggest coin that is not more than 87p. Using the biggest coins each time gives the fewest coins.Take 50p. 87p − 50p = 37p left
- Take the biggest coin that is not more than 37p. Using the biggest coins each time gives the fewest coins.Take 20p. 37p − 20p = 17p left
- Take the biggest coin that is not more than 17p. Using the biggest coins each time gives the fewest coins.Take 10p. 17p − 10p = 7p left
- Take the biggest coin that is not more than 7p. Using the biggest coins each time gives the fewest coins.Take 5p. 7p − 5p = 2p left
- Take the biggest coin that is not more than 2p. Using the biggest coins each time gives the fewest coins.Take 2p. 2p − 2p = 0p left
- Write the coins. Check the amount: they should add up to £1.87.£1, 50p, 20p, 10p, 5p, 2p (6 coins)
Check. Add the coins: 100p + 50p + 20p + 10p + 5p + 2p = 187p = £1.87. ✓
Watch out. Do not use lots of small coins. Always take the biggest coin that fits.
Watch out
Two digits for the pence. £5.05 is 5 pounds and 5 pence. £5.5 would mean £5.50. And when you compare, do not compare 95 with 1.05 as they are: change to the same unit. 95p is LESS than £1.05 even though 95 is a bigger number than 1.05.Exercise 6F Money: pounds and pence
Non-calculatorKey words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Count how much each kind of coin or note is worth in pence. Add the amounts. Then write the total in pounds and pence.
- Count each kind of note and coin. Group the same ones together. Change each group into pence.1 × 50p = 50p
1 × 20p = 20p
1 × 10p = 10p
1 × 5p = 5p
1 × 2p = 2p
1 × 1p = 1p - Add the groups, biggest first. Adding the big amounts first is easier. Keep a running total.50p
50p + 20p = 70p
70p + 10p = 80p
80p + 5p = 85p
85p + 2p = 87p
87p + 1p = 88p - Write the total. 100p = £1, so change to pounds and pence if it is 100p or more.88p
Check. Add in a different order, smallest first: 1p + 2p + 5p + 10p + 20p + 50p = 88p. ✓
Watch out. Change everything to pence first. Do not add pounds and pence together as if they were the same.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Count how much each kind of coin or note is worth in pence. Add the amounts. Then write the total in pounds and pence.
- Count each kind of note and coin. Group the same ones together. Change each group into pence.1 × £2 = 200p
1 × £1 = 100p
2 × 50p = 100p
1 × 20p = 20p - Add the groups, biggest first. Adding the big amounts first is easier. Keep a running total.200p
200p + 100p = 300p
300p + 100p = 400p
400p + 20p = 420p - Write the total. 100p = £1, so change to pounds and pence if it is 100p or more.420p = £4.20
Check. Add in a different order, smallest first: 20p + 50p + 50p + 100p + 200p = 420p. ✓
Watch out. Change everything to pence first. Do not add pounds and pence together as if they were the same.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Count how much each kind of coin or note is worth in pence. Add the amounts. Then write the total in pounds and pence.
- Count each kind of note and coin. Group the same ones together. Change each group into pence.1 × £10 = 1000p
1 × £5 = 500p
1 × £1 = 100p
2 × 20p = 40p
1 × 5p = 5p - Add the groups, biggest first. Adding the big amounts first is easier. Keep a running total.1000p
1000p + 500p = 1500p
1500p + 100p = 1600p
1600p + 40p = 1640p
1640p + 5p = 1645p - Write the total. 100p = £1, so change to pounds and pence if it is 100p or more.1645p = £16.45
Check. Add in a different order, smallest first: 5p + 20p + 20p + 100p + 500p + 1000p = 1645p. ✓
Watch out. Change everything to pence first. Do not add pounds and pence together as if they were the same.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Divide the pence by 100 to find the pounds. The pence left over go after the decimal point, with two digits.
- Remember: 100 pence make 1 pound. So we divide the pence by 100 to find the pounds.250 ÷ 100 = 2 remainder 50
- Write the pounds and the pence. 2 pounds and 50p.2 pounds and 50p
- Put them together with a decimal point. The pence always get two digits after the decimal point.£2.50
Check. Go back: £2.50 = 2 × 100 + 50 = 250p. ✓
Watch out. Do not write £2.5: money always has two digits after the point.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Divide the pence by 100 to find the pounds. The pence left over go after the decimal point, with two digits.
- Remember: 100 pence make 1 pound. So we divide the pence by 100 to find the pounds.605 ÷ 100 = 6 remainder 5
- Write the pounds and the pence. 6 pounds and 5p.6 pounds and 5p
- Put them together with a decimal point. The pence always get TWO digits: write a 0 in front if there is only one.£6.05 (the 0 holds the tens-of-pence place)
Check. Go back: £6.05 = 6 × 100 + 5 = 605p. ✓
Watch out. Do not write £6.5: money always has two digits after the point.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Divide the pence by 100 to find the pounds. The pence left over go after the decimal point, with two digits.
- Remember: 100 pence make 1 pound. So we divide the pence by 100 to find the pounds.90 ÷ 100 = 0 remainder 90
- Write the pounds and the pence. The amount is less than 100p, so there are no whole pounds.0 pounds and 90p
- Put them together with a decimal point. The pence always get two digits after the decimal point.£0.90
Check. Go back: £0.90 = 0 × 100 + 90 = 90p. ✓
Watch out. Do not write £0.9: money always has two digits after the point.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Divide the pence by 100 to find the pounds. The pence left over go after the decimal point, with two digits.
- Remember: 100 pence make 1 pound. So we divide the pence by 100 to find the pounds.7 ÷ 100 = 0 remainder 7
- Write the pounds and the pence. The amount is less than 100p, so there are no whole pounds.0 pounds and 7p
- Put them together with a decimal point. The pence always get TWO digits: write a 0 in front if there is only one.£0.07 (the 0 holds the tens-of-pence place)
Check. Go back: £0.07 = 0 × 100 + 7 = 7p. ✓
Watch out. Do not write £0.7: money always has two digits after the point.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Divide the pence by 100 to find the pounds. The pence left over go after the decimal point, with two digits.
- Remember: 100 pence make 1 pound. So we divide the pence by 100 to find the pounds.1205 ÷ 100 = 12 remainder 5
- Write the pounds and the pence. 12 pounds and 5p.12 pounds and 5p
- Put them together with a decimal point. The pence always get TWO digits: write a 0 in front if there is only one.£12.05 (the 0 holds the tens-of-pence place)
Check. Go back: £12.05 = 12 × 100 + 5 = 1205p. ✓
Watch out. Do not write £12.5: money always has two digits after the point.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Divide the pence by 100 to find the pounds. The pence left over go after the decimal point, with two digits.
- Remember: 100 pence make 1 pound. So we divide the pence by 100 to find the pounds.480 ÷ 100 = 4 remainder 80
- Write the pounds and the pence. 4 pounds and 80p.4 pounds and 80p
- Put them together with a decimal point. The pence always get two digits after the decimal point.£4.80
Check. Go back: £4.80 = 4 × 100 + 80 = 480p. ✓
Watch out. Do not write £4.8: money always has two digits after the point.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Multiply the pounds by 100 and add the pence.
- Remember: 1 pound is 100 pence. So we multiply the pounds by 100.4 × 100 = 400p
- Add the pence. The two digits after the decimal point are the pence.400p + 20p = 420p
- Write the answer with the unit p. Pence are written with a small p after the number.£4.20 = 420p
Check. Go back: 420p ÷ 100 = £4.20. ✓
Watch out. Be careful with the 0s: money to pence moves the digits two places to the left.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Multiply the pounds by 100 and add the pence.
- Remember: 1 pound is 100 pence. So we multiply the pounds by 100.0 × 100 = 0p
- Add the pence. The two digits after the decimal point are the pence.0p + 65p = 65p
- Write the answer with the unit p. Pence are written with a small p after the number.£0.65 = 65p
Check. Go back: 65p ÷ 100 = £0.65. ✓
Watch out. Be careful with the 0s: money to pence moves the digits two places to the left.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Multiply the pounds by 100 and add the pence.
- Remember: 1 pound is 100 pence. So we multiply the pounds by 100.6 × 100 = 600p
- Add the pence. The two digits after the decimal point are the pence.600p + 5p = 605p
- Write the answer with the unit p. Pence are written with a small p after the number.£6.05 = 605p
Check. Go back: 605p ÷ 100 = £6.05. ✓
Watch out. £6.05 is 605p, not 65p: if the pence are less than 10, put a 0 in: £6.05 = 605p.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Multiply the pounds by 100 and add the pence.
- Remember: 1 pound is 100 pence. So we multiply the pounds by 100.0 × 100 = 0p
- Add the pence. The two digits after the decimal point are the pence.0p + 8p = 8p
- Write the answer with the unit p. Pence are written with a small p after the number.£0.08 = 8p
Check. Go back: 8p ÷ 100 = £0.08. ✓
Watch out. £0.08 is 8p, not 08p: if the pence are less than 10, put a 0 in: £0.08 = 8p.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Multiply the pounds by 100 and add the pence.
- Remember: 1 pound is 100 pence. So we multiply the pounds by 100.12 × 100 = 1200p
- Add the pence. The two digits after the decimal point are the pence.1200p + 30p = 1230p
- Write the answer with the unit p. Pence are written with a small p after the number.£12.30 = 1230p
Check. Go back: 1230p ÷ 100 = £12.30. ✓
Watch out. Be careful with the 0s: money to pence moves the digits two places to the left.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Multiply the pounds by 100 and add the pence.
- Remember: 1 pound is 100 pence. So we multiply the pounds by 100.3 × 100 = 300p
- Add the pence. The two digits after the decimal point are the pence.300p + 0p = 300p
- Write the answer with the unit p. Pence are written with a small p after the number.£3.00 = 300p
Check. Go back: 300p ÷ 100 = £3.00. ✓
Watch out. Be careful with the 0s: money to pence moves the digits two places to the left.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Write the pounds, then a decimal point, then the pence using two digits.
- Write the pounds. The pounds go before the decimal point.£3
- Write the pence with two digits. Money always has two digits after the point. Use a 0 in front for pence under 10.40p = .40
- Put them together. £3.40
Check. £3.40 = 340p = 3 pounds and 40p. ✓
Watch out. Two digits after the point, always.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Write the pounds, then a decimal point, then the pence using two digits.
- Write the pounds. The pounds go before the decimal point.£5
- Write the pence with two digits. Money always has two digits after the point. Use a 0 in front for pence under 10.5p = .05
- Put them together. £5.05
Check. £5.05 = 505p = 5 pounds and 5p. ✓
Watch out. 5 pounds and 5 pence is £5.05, not £5.5. The 0 is needed.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Write the pounds, then a decimal point, then the pence using two digits.
- Write the pounds. The pounds go before the decimal point.£0
- Write the pence with two digits. Money always has two digits after the point. Use a 0 in front for pence under 10.65p = .65
- Put them together. £0.65
Check. £0.65 = 65p = 0 pounds and 65p. ✓
Watch out. Two digits after the point, always.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Write the pounds, then a decimal point, then the pence using two digits.
- Write the pounds. The pounds go before the decimal point.£12
- Write the pence with two digits. Money always has two digits after the point. Use a 0 in front for pence under 10.9p = .09
- Put them together. £12.09
Check. £12.09 = 1209p = 12 pounds and 9p. ✓
Watch out. 5 pounds and 5 pence is £5.05, not £5.5. The 0 is needed.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Money needs two digits after the decimal point. Add a 0 on the end.
- Look at what Amira wrote. Count the digits after the decimal point.£4.5 has only one digit after the point.
- Think about money. Pence need two digits: tens of pence and pence.50p is 5 tens of pence and 0 pence.
- Write it correctly. Add the 0 for the pence.£4.5 → £4.50
Check. Say it in words: £4.50 is 4 pounds and 50 pence. ✓
Watch out. A calculator shows 4.5, but money is written £4.50.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Pence need two digits. Single-digit pence need a 0 in front.
- Look at what Amira wrote. Amira wrote 5 pence after the point as a single digit.£5.5 means 5 pounds and 50p, which is £5.50.
- Think about the pence. 5p is less than 10p. The tens-of-pence place needs a 0.0 tens of pence and 5 pence
- Write it correctly. Two digits for the pence: 0 then 5.£5.5 → £5.05
Check. Say it in words: £5.05 is 5 pounds and 5 pence. ✓
Watch out. £5.5 is £5.50. For 5p you must write £5.05.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Use the pound sign with a decimal point, OR the p sign. Never both.
- Look at what Amira wrote. Look at the signs.£0.45p has a pound sign AND a p.
- Think about the symbols. The pound sign and the decimal point already say these are pounds. The p says pence. We only use one of them.£0.45 means 45 pence, and 45p also means 45 pence.
- Write it correctly. Use either pounds or pence.£0.45 or 45p
Check. £0.45 is 45 pence. ✓
Watch out. Never write both £ and p together.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Money needs two digits after the decimal point. Add a 0 on the end.
- Look at what Amira wrote. Count the digits after the decimal point.£20.3 has only one digit after the point.
- Think about money. Pence need two digits: tens of pence and pence.30p is 3 tens of pence and 0 pence.
- Write it correctly. Add the 0 for the pence.£20.3 → £20.30
Check. Say it in words: £20.30 is 20 pounds and 30 pence. ✓
Watch out. A calculator shows 4.5, but money is written £4.50.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change both amounts into the same unit (pence). Then compare the numbers.
- Change both amounts to pence. We can only compare money when it is in the same unit. To change pounds to pence, multiply by 100.£2.50 = 250p (£2 × 100 + 50 = 250)
250p = 250p - Compare the numbers of pence. The bigger number of pence is the bigger amount.250 = 250
- Write the answer. £2.50 = 250p
Check. Picture £2.50 and 250p as coins: the same money in the first. ✓
Watch out. Do not compare 3.40 with 304 as they are. Change to the same unit first: 340p and 304p.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change both amounts into the same unit (pence). Then compare the numbers.
- Change both amounts to pence. We can only compare money when it is in the same unit. To change pounds to pence, multiply by 100.£3.05 = 305p (£3 × 100 + 5 = 305)
350p = 350p - Compare the numbers of pence. The bigger number of pence is the bigger amount.305 < 350
- Write the answer. £3.05 < 350p
Check. Picture £3.05 and 350p as coins: less money in the first. ✓
Watch out. Do not compare 3.40 with 304 as they are. Change to the same unit first: 340p and 304p.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change both amounts into the same unit (pence). Then compare the numbers.
- Change both amounts to pence. We can only compare money when it is in the same unit. To change pounds to pence, multiply by 100.99p = 99p
£1.00 = 100p (£1 × 100 + 0 = 100) - Compare the numbers of pence. The bigger number of pence is the bigger amount.99 < 100
- Write the answer. 99p < £1.00
Check. Picture 99p and £1.00 as coins: less money in the first. ✓
Watch out. Do not compare 3.40 with 304 as they are. Change to the same unit first: 340p and 304p.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change both amounts into the same unit (pence). Then compare the numbers.
- Change both amounts to pence. We can only compare money when it is in the same unit. To change pounds to pence, multiply by 100.£1.75 = 175p (£1 × 100 + 75 = 175)
157p = 157p - Compare the numbers of pence. The bigger number of pence is the bigger amount.175 > 157
- Write the answer. £1.75 > 157p
Check. Picture £1.75 and 157p as coins: more money in the first. ✓
Watch out. Do not compare 3.40 with 304 as they are. Change to the same unit first: 340p and 304p.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change both amounts into the same unit (pence). Then compare the numbers.
- Change both amounts to pence. We can only compare money when it is in the same unit. To change pounds to pence, multiply by 100.£0.60 = 60p (£0 × 100 + 60 = 60)
6p = 6p - Compare the numbers of pence. The bigger number of pence is the bigger amount.60 > 6
- Write the answer. £0.60 > 6p
Check. Picture £0.60 and 6p as coins: more money in the first. ✓
Watch out. Do not compare 3.40 with 304 as they are. Change to the same unit first: 340p and 304p.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change every amount to pence. Put the numbers in order. Then write the amounts the way they were first written.
- Change every amount to pence. The amounts are in different units, so we change them all to pence (£1 = 100p).£2.50 = 250p
199p = 199p
£2.05 = 205p
90p = 90p - Put the numbers of pence in order. We want smallest first.90p, 199p, 205p, 250p
- Write the original amounts in that order. Use the way each amount was written in the question.90p, 199p, £2.05, £2.50
Check. Count them: 4 amounts in the question and 4 in the answer. ✓
Watch out. Do not mix up pence and pounds: 95p is less than £1.05 even though 95 is bigger than 1.05.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change every amount to pence. Put the numbers in order. Then write the amounts the way they were first written.
- Change every amount to pence. The amounts are in different units, so we change them all to pence (£1 = 100p).£3.05 = 305p
£0.03 = 3p
35p = 35p
350p = 350p - Put the numbers of pence in order. We want biggest first.350p, 305p, 35p, 3p
- Write the original amounts in that order. Use the way each amount was written in the question.350p, £3.05, 35p, £0.03
Check. Count them: 4 amounts in the question and 4 in the answer. ✓
Watch out. Do not mix up pence and pounds: 95p is less than £1.05 even though 95 is bigger than 1.05.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change every amount to pence. Put the numbers in order. Then write the amounts the way they were first written.
- Change every amount to pence. The amounts are in different units, so we change them all to pence (£1 = 100p).85p = 85p
£2.40 = 240p
£1.15 = 115p
60p = 60p - Put the numbers of pence in order. We want smallest first.60p, 85p, 115p, 240p
- Write the original amounts in that order. Use the way each amount was written in the question.60p, 85p, £1.15, £2.40
- Pick the last one in the list. This is the biggest amount.£2.40
Check. Count them: 4 amounts in the question and 4 in the answer. ✓
Watch out. Do not mix up pence and pounds: 95p is less than £1.05 even though 95 is bigger than 1.05.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change every amount to pence. Put the numbers in order. Then write the amounts the way they were first written.
- Change every amount to pence. The amounts are in different units, so we change them all to pence (£1 = 100p).85p = 85p
£2.40 = 240p
£1.15 = 115p
60p = 60p - Put the numbers of pence in order. We want smallest first.60p, 85p, 115p, 240p
- Write the original amounts in that order. Use the way each amount was written in the question.60p, 85p, £1.15, £2.40
- Pick the first one in the list. This is the smallest amount.60p
Check. Count them: 4 amounts in the question and 4 in the answer. ✓
Watch out. Do not mix up pence and pounds: 95p is less than £1.05 even though 95 is bigger than 1.05.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change every amount to pence. Put the numbers in order. Then write the amounts the way they were first written.
- Change every amount to pence. The amounts are in different units, so we change them all to pence (£1 = 100p).85p = 85p
£2.40 = 240p
£1.15 = 115p
60p = 60p - Put the numbers of pence in order. We want biggest first.240p, 115p, 85p, 60p
- Write the original amounts in that order. Use the way each amount was written in the question.£2.40, £1.15, 85p, 60p
Check. Count them: 4 amounts in the question and 4 in the answer. ✓
Watch out. Do not mix up pence and pounds: 95p is less than £1.05 even though 95 is bigger than 1.05.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Start with the biggest coin that fits. Take it away, then do the same with what is left. Keep going until nothing is left.
- Take the biggest coin that is not more than 38p. Using the biggest coins each time gives the fewest coins.Take 20p. 38p − 20p = 18p left
- Take the biggest coin that is not more than 18p. Using the biggest coins each time gives the fewest coins.Take 10p. 18p − 10p = 8p left
- Take the biggest coin that is not more than 8p. Using the biggest coins each time gives the fewest coins.Take 5p. 8p − 5p = 3p left
- Take the biggest coin that is not more than 3p. Using the biggest coins each time gives the fewest coins.Take 2p. 3p − 2p = 1p left
- Take the biggest coin that is not more than 1p. Using the biggest coins each time gives the fewest coins.Take 1p. 1p − 1p = 0p left
- Write the coins. Check the amount: they should add up to 38p.20p, 10p, 5p, 2p, 1p (5 coins)
Check. Add the coins: 20p + 10p + 5p + 2p + 1p = 38p = 38p. ✓
Watch out. Do not use lots of small coins. Always take the biggest coin that fits.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Start with the biggest coin that fits. Take it away, then do the same with what is left. Keep going until nothing is left.
- Take the biggest coin that is not more than 74p. Using the biggest coins each time gives the fewest coins.Take 50p. 74p − 50p = 24p left
- Take the biggest coin that is not more than 24p. Using the biggest coins each time gives the fewest coins.Take 20p. 24p − 20p = 4p left
- Take the biggest coin that is not more than 4p. Using the biggest coins each time gives the fewest coins.Take 2p. 4p − 2p = 2p left
- Take the biggest coin that is not more than 2p. Using the biggest coins each time gives the fewest coins.Take 2p. 2p − 2p = 0p left
- Write the coins. Check the amount: they should add up to 74p.50p, 20p, 2p, 2p (4 coins)
Check. Add the coins: 50p + 20p + 2p + 2p = 74p = 74p. ✓
Watch out. Do not use lots of small coins. Always take the biggest coin that fits.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Start with the biggest coin that fits. Take it away, then do the same with what is left. Keep going until nothing is left.
- Take the biggest coin that is not more than 143p. Using the biggest coins each time gives the fewest coins.Take £1. 143p − 100p = 43p left
- Take the biggest coin that is not more than 43p. Using the biggest coins each time gives the fewest coins.Take 20p. 43p − 20p = 23p left
- Take the biggest coin that is not more than 23p. Using the biggest coins each time gives the fewest coins.Take 20p. 23p − 20p = 3p left
- Take the biggest coin that is not more than 3p. Using the biggest coins each time gives the fewest coins.Take 2p. 3p − 2p = 1p left
- Take the biggest coin that is not more than 1p. Using the biggest coins each time gives the fewest coins.Take 1p. 1p − 1p = 0p left
- Write the coins. Check the amount: they should add up to £1.43.£1, 20p, 20p, 2p, 1p (5 coins)
Check. Add the coins: 100p + 20p + 20p + 2p + 1p = 143p = £1.43. ✓
Watch out. Do not use lots of small coins. Always take the biggest coin that fits.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change the total into pence. Then divide by the value of one coin.
- Change the total to pence. The coin is in pence, so use pence for both.£3.00 = 300p
- Divide the total by the value of one coin. We want to know how many 20p coins fit into 300p.300 ÷ 20 = 15
- Write the answer. 15 coins
Check. Go back: 15 × 20p = 300p. ✓
Watch out. Use the times tables: for 20p, think of 2 tens. 5 coins of 20p make 100p.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change the total into pence. Then divide by the value of one coin.
- Change the total to pence. The coin is in pence, so use pence for both.£8.00 = 800p
- Divide the total by the value of one coin. We want to know how many 50p coins fit into 800p.800 ÷ 50 = 16
- Write the answer. 16 coins
Check. Go back: 16 × 50p = 800p. ✓
Watch out. Use the times tables: for 20p, think of 2 tens. 5 coins of 20p make 100p.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change the total into pence. Then divide by the value of one coin.
- Change the total to pence. The coin is in pence, so use pence for both.£2.00 = 200p
- Divide the total by the value of one coin. We want to know how many 5p coins fit into 200p.200 ÷ 5 = 40
- Write the answer. 40 coins
Check. Go back: 40 × 5p = 200p. ✓
Watch out. Use the times tables: for 20p, think of 2 tens. 5 coins of 20p make 100p.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Count how much each kind of coin or note is worth in pence. Add the amounts. Then write the total in pounds and pence.
- Count each kind of note and coin. Group the same ones together. Change each group into pence.2 × £1 = 200p
3 × 50p = 150p
5 × 20p = 100p
4 × 10p = 40p - Add the groups, biggest first. Adding the big amounts first is easier. Keep a running total.200p
200p + 150p = 350p
350p + 100p = 450p
450p + 40p = 490p - Write the total. 100p = £1, so change to pounds and pence if it is 100p or more.490p = £4.90
Check. Add in a different order, smallest first: 10p + 10p + 10p + 10p + 20p + 20p + 20p + 20p + 20p + 50p + 50p + 50p + 100p + 100p = 490p. ✓
Watch out. Change everything to pence first. Do not add pounds and pence together as if they were the same.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. List the amounts that can be made with 5p and 10p coins. Look at the last digit.
- Look at what 5p and 10p coins are worth. Every 5p coin is worth 5p and every 10p coin is worth 10p.5, 10, 15, 20, 25 ... all end in 5 or 0
- Think about adding them. Adding amounts that end in 5 or 0 gives an amount that ends in 5 or 0.5p + 10p = 15p 10p + 10p = 20p 5p + 5p = 10p
- Look at 47p. It ends in 7.No. 47p ends in 7, so it cannot be made from 5p and 10p coins.
Check. 47 is not in the 5 times table. ✓
Watch out. Use the last digit to check.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. The coins are worth 35p in total. Try the biggest coins first.
- Try the biggest coin that fits. The coins cannot be more than 35p. The biggest coin that is not more than 35p is 20p.20p, and 35p − 20p = 15p left for two coins
- Find two coins that make 15p. The biggest coin not more than 15p is 10p. Then 5p is left.10p + 5p = 15p
- Write the answer. 20p, 10p and 5p
Check. 20p + 10p + 5p = 35p and there are 3 coins. ✓
Watch out. Start with the biggest coin that fits, as in the fewest coins method.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Find five coins that add up to 100p. Try a big coin first, then fill the gap.
- Way 1: start with 50p. That leaves 50p for 4 coins. 20p + 10p + 10p + 10p = 50p.50p + 20p + 10p + 10p + 10p = 100p
- Way 2: start with 50p again but use different coins. 50p is left for 4 coins. 20p + 20p + 5p + 5p = 50p.50p + 20p + 20p + 5p + 5p = 100p
- Way 3: use only one kind of coin. 100p ÷ 5 = 20p, so five 20p coins.20p + 20p + 20p + 20p + 20p = 100p
Check. Each way uses 5 coins and the total is 100p = £1. ✓
Watch out. There are other correct ways. Check every one adds up to 100p and uses exactly 5 coins.
Adding, subtracting and money problems
Printable: Worksheet (PDF) · Answers (PDF) · Open this lesson on its own page
Adding money. Write the amounts in columns with the decimal points in a straight line, so pounds are under pounds and pence are under pence. Add the pence first, then the pounds. If the pence make 100p or more, carry 1 to the pounds, as you do with any column addition (Chapter 2).
For example, to add £2.75 and £1.86 we write the numbers like this. The decimal points are in a straight line.
| £1 | 10p | 1p | ||
| £ | 2 | . | 7 | 5 |
| + £ | 1 | . | 8 | 6 |
| £ | . | |||
A good check is to estimate: round each amount to the nearest pound. £2.75 is about £3 and £1.86 is about £2, so the total is about £5.
Another way. Add the pounds and the pence separately. £3.85 + £2.47: pounds 3 + 2 = 5. Pence 85 + 47 = 132p = £1.32. Then £5 + £1.32 = £6.32.
Subtracting money is the same as column subtraction: the bigger amount goes on top. If the pence are too small, exchange 1 pound for 100p.
Here is £8.30 − £4.65 set out in columns.
| £1 | 10p | 1p | ||
| £ | 8 | . | 3 | 0 |
| − £ | 4 | . | 6 | 5 |
| £ | . |
Change. The change is the money you get back when you pay with more than the cost. Change = money paid − total cost. You can subtract, or count up from the cost to the money paid: first to the next whole pound, then up in whole pounds.
Multiplying and sharing. For 3 items that cost £1.35 each, multiply the pounds and the pence separately: 3 × £1 = £3 and 3 × 35p = 105p = £1.05. The total is £4.05. To share £7.20 equally between 4 people, change to pence: 720p ÷ 4 = 180p = £1.80 each.
Measures with decimals. You can add and subtract lengths, masses and capacities written as decimals in the same way. Line up the decimal points. 2.5 m has one decimal place and 1.75 m has two, so write 2.5 as 2.50. Then 2.50 + 1.75 = 4.25 m.
Multi-step problems. Draw a bar model. Work out what you need to find first, and do the calculations in order.
Key words. The total is all the amounts added together. Change is the money you get back. To estimate is to find an approximate answer by rounding. Carry and exchange are column-method tricks.
Key ideas
- Line up the decimal points. Pounds under pounds, pence under pence.
- Add or subtract the pence first, then the pounds. Carry or exchange when you need to.
- Change = money paid − total cost. You can also count up from the cost.
- Multiply the pounds and the pence separately. Change 100p into £1.
- To share money equally, change to pence and divide. Change back to pounds.
- Estimate first: round each amount to the nearest pound to check the answer.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the amounts in columns with the decimal points lined up. Add the pence first, then the pounds. Carry when a column makes 10 or more.
- Line up the amounts in columns. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 2 . 7 5 + £ 1 . 8 6 £ . - Add the pence. Always start on the right.5 + 6 = 11
11 is 10 or more. Write 1 in the pence column and carry 1 to the tens of pence column. - Add the tens of pence. Now the next column to the left. Add the 1 we carried as well.7 + 8 + 1 = 16
16 is 10 or more. Write 6 in the tens of pence column and carry 1 to the pounds column (across the decimal point). - Add the pounds. Now the next column to the left. Add the 1 we carried as well.2 + 1 + 1 = 4
4 is less than 10, so write 4. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 2 . 7 5 + £ 1 . 8 6 £ 4 . 6 1 1 1
£2.75 + £1.86 = £4.61
Check. Estimate: round to the nearest pound: £3 + £2 = £5. This is close to £4.61. ✓
Watch out. Line up the decimal points. Write £5.00 for a whole number of pounds, so the digits line up.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Add the pounds, then add the pence. If the pence make 100p or more, change 100p into another pound.
- Split each amount into pounds and pence. We add the pounds and the pence separately.£3.85 = £3 + 85p
£2.47 = £2 + 47p - Add the pounds. Add the whole pound parts.£3 + £2 = £5
- Add the pence. Add the pence parts.85p + 47p = 132p
- Change 100 pence into a pound. The pence total is 100p or more. Every 100p is £1.132p = £1 and 32p
£5 + £1 = £6 - Put the pounds and pence together. £6 and 32p = £6.32
Check. Estimate: round to the nearest pound: £4 + £2 = £6. This is close to £6.32. ✓
Watch out. If the pence add up to more than 100p, you must change 100p into £1. Do not write £5.113.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the bigger amount on top with the decimal points lined up. Subtract the pence first, then the pounds. Exchange if a top digit is too small.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 8 . 3 0 − £ 4 . 6 5 £ . - Exchange, then subtract the pence. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
Exchange 1 from the tens of pence column: 3 becomes 2, and the pence column goes from 0 to 10.
10 − 5 = 5 - Exchange, then subtract the tens of pence. The top digit is smaller than the bottom digit, so we swap 1 from the next column.2 is not enough to take away 6. We need to exchange.
(There were 3 in this column to start with, but we gave one away in an earlier exchange.)
Exchange 1 from the pounds column: 8 becomes 7, and the tens of pence column goes from 2 to 12. (This crosses the decimal point.)
12 − 6 = 6 - Subtract the pounds. Now the next column to the left.(This digit is 7 now, not 8, because we exchanged from this column.)
7 − 4 = 3 - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 7 8. 12 310 0− £ 4 . 6 5 £ 3 . 6 5
£8.30 − £4.65 = £3.65
Check. Add back: £3.65 + £4.65 = £8.30. ✓
Estimate: £8 − £5 = £3, close to £3.65.
Watch out. Take the bottom number from the top number. Exchange 1 pound for 100p when the pence are not enough.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the bigger amount on top with the decimal points lined up. Subtract the pence first, then the pounds. Exchange if a top digit is too small.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£10 £1 10p 1p £ 1 0 . 0 0 − £ 4 . 3 5 £ . - Exchange, then subtract the pence. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
The columns in between have 0, so we start further left and pass the exchange along one column at a time. Each 0 in the middle becomes 9.
Exchange 1 from the tens of pounds column: 1 becomes 0, and the pounds column goes from 0 to 10.
Exchange 1 from the pounds column: 10 becomes 9, and the tens of pence column goes from 0 to 10. (This crosses the decimal point.)
Exchange 1 from the tens of pence column: 10 becomes 9, and the pence column goes from 0 to 10.
10 − 5 = 5 - Subtract the tens of pence. Now the next column to the left.(This digit is 9 now, not 0, because we exchanged from this column.)
9 − 3 = 6 - Subtract the pounds. Now the next column to the left.(This digit is 9 now, not 0, because we exchanged from this column.)
9 − 4 = 5 - Bring down the tens of pounds digit. The bottom number has no digit in this column.(This digit is 0 now, not 1, because we exchanged from this column.)
Nothing to take away here, so the digit stays: 0. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£10 £1 10p 1p £ 0 19 0. 9 010 0− £ 4 . 3 5 £ 5 . 6 5
£10.00 − £4.35 = £5.65
Check. Add back: £5.65 + £4.35 = £10.00. ✓
Estimate: £10 − £4 = £6, close to £5.65.
Watch out. Take the bottom number from the top number. Exchange 1 pound for 100p when the pence are not enough.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Add up the cost of everything. Then take the total cost away from the money that was paid. What is left is the change.
- Draw a bar model. The whole bar is the money we pay with. It is split into the cost of what we buy and the change.
- Step 1: find the total cost. Add all the prices.£1.45 + £0.65 = £2.10
£1 10p 1p £ 1 . 4 5 + £ 0 . 6 5 £ 2 . 1 0 1 1 - Step 2: find the change. Take the cost away from the money paid.£5.00 − £2.10 = £2.90
£1 10p 1p £ 4 5. 10 00 − £ 2 . 1 0 £ 2 . 9 0 - Write the answer. The change is £2.90
Check. Add the change to the cost: £2.10 + £2.90 = £5.00, the money paid. ✓
Watch out. Take away the TOTAL cost, not just one price.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Count up from the cost to the money paid. First jump to the next whole pound, then jump in whole pounds. Add the jumps.
- Start at the cost. We count up from what we spent to the money we paid. The jumps add up to the change.Start at £13.40
- Jump up to the next whole pound. This makes the next jump easier.£13.40 + 60p = £14.00
- Jump up to the money paid. Count on in whole pounds.£14.00 + £6 = £20.00
- Draw the jumps on a number line.
- Add up the jumps. The total of the jumps is the change.60p + £6 = £6.60
Check. Subtract: £20.00 − £13.40 = £6.60. ✓
Watch out. Keep the jumps small and friendly: pence to the next pound, then pounds.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Multiply the pounds and the pence separately. Change any pence over 100p into pounds. Then add the parts.
- Split the price into pounds and pence. It is easier to multiply each part.£1.35 = £1 + 35p
- Multiply the pounds. 3 lots of £1.£1 × 3 = £3
- Multiply the pence. 3 lots of 35p.35p × 3 = 105p
- Change the pence into pounds. 100p = £1.105p = £1 and 5p = £1.05
- Add the parts together. £3 + £1.05 = £4.05
Check. Estimate: £1.35 is about £1, and 3 × £1 = £3, close to £4.05. ✓
Watch out. Write the answer with two decimal places, and change pence over 100p into pounds.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change the money into pence. Divide by the number of shares. Change the answer back to pounds and pence.
- Change the amount to pence. Pence are whole numbers, so they are easier to divide.£7.20 = 720p
- Divide by 4. Sharing equally into 4 means dividing by 4.720p ÷ 4 = 180p
- Change back to pounds and pence. 100p = £1.180p = £1.80
Check. Go back: £1.80 × 4 = £7.20. ✓
Watch out. Do not divide the pounds and pence as if they were one number. Change to pence first.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Find the cost of each group of items. Add them to find the total. Then take the total away from the money paid to find the change.
- Find the cost of 3 pens. 3 lots of £0.85.3 × £0.85 = £2.55 (85p × 3 = 255p)
- Add the costs to find the total. Use a column method, with the decimal points lined up.£2.55 + £1.50 = £4.05
£1 10p 1p £ 2 . 5 5 + £ 1 . 5 0 £ 4 . 0 5 1 - Take the total cost away from the money paid. What is left is the change.£10.00 − £4.05 = £5.95
£10 £1 10p 1p £ 0 19 0. 9 010 0− £ 4 . 0 5 £ 5 . 9 5 - Write the answer. The change is £5.95
Check. Add the change to the total: £4.05 + £5.95 = £10.00. ✓
Watch out. Multiply first, then add, then subtract from the money paid.
Key words. Lengths, masses and capacities can be written as decimals: 2.5 m is two and a half metres, 1.75 kg is 1 and 3/4 kilograms. Line up the decimal points to add or subtract.
Method. Line up the decimal points. Add column by column from the right. Carry when a column makes 10 or more. Write the unit.
- Give both numbers the same number of decimal places. Adding a 0 on the end of a decimal does not change its value. It helps the digits line up.2.5 = 2.50
- Line up the amounts in columns. Put the decimal points in a straight line, so tenths are under tenths and ones under ones.
O t h 1 . 7 5 + 2 . 5 0 . - Add the hundredths. Always start on the right.5 + 0 = 5
5 is less than 10, so write 5. There is nothing to carry. - Add the tenths. Now the next column to the left.7 + 5 = 12
12 is 10 or more. Write 2 in the tenths column and carry 1 to the ones column (across the decimal point). - Add the ones. Now the next column to the left. Add the 1 we carried as well.1 + 2 + 1 = 4
4 is less than 10, so write 4. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
O t h 1 . 7 5 + 2 . 5 0 4 . 2 5 1
1.75 kg + 2.50 kg = 4.25 kg
Check. Take away: 4.25 kg − 2.50 kg = 1.75 kg. ✓
Watch out. Line up the decimal points, not the right-hand digits: 2.5 has fewer digits than 1.75, so write 2.50.
Key words. Lengths, masses and capacities can be written as decimals: 2.5 m is two and a half metres, 1.75 kg is 1 and 3/4 kilograms. Line up the decimal points to add or subtract.
Method. Line up the decimal points with the bigger number on top. Subtract column by column from the right. Exchange when a top digit is too small. Write the unit.
- Give both numbers the same number of decimal places. Adding a 0 on the end of a decimal does not change its value. It helps the digits line up.3.2 = 3.20
- Line up the amounts in columns. The bigger number goes on top. Put the decimal points in a straight line.
O t h 3 . 2 0 − 1 . 4 5 . - Exchange, then subtract the hundredths. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
Exchange 1 from the tenths column: 2 becomes 1, and the hundredths column goes from 0 to 10.
10 − 5 = 5 - Exchange, then subtract the tenths. The top digit is smaller than the bottom digit, so we swap 1 from the next column.1 is not enough to take away 4. We need to exchange.
(There were 2 in this column to start with, but we gave one away in an earlier exchange.)
Exchange 1 from the ones column: 3 becomes 2, and the tenths column goes from 1 to 11. (This crosses the decimal point.)
11 − 4 = 7 - Subtract the ones. Now the next column to the left.(This digit is 2 now, not 3, because we exchanged from this column.)
2 − 1 = 1 - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
O t h 2 3. 11 210 0− 1 . 4 5 1 . 7 5
3.20 m − 1.45 m = 1.75 m
Check. Add back: 1.75 m + 1.45 m = 3.20 m. ✓
Watch out. Line up the decimal points, not the right-hand digits: 2.5 has fewer digits than 1.75, so write 2.50.
Watch out
Line up the decimal points, not the last digits. £5 + £2.35 must be written £5.00 + £2.35. And if the pence add up to more than 99p, change 100p into £1: £3.65 + £2.48 is £6.13, not £5.113.Exercise 6G Adding, subtracting and change
Non-calculatorKey words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the amounts in columns with the decimal points lined up. Add the pence first, then the pounds. Carry when a column makes 10 or more.
- Line up the amounts in columns. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 1 . 3 0 + £ 2 . 4 5 £ . - Add the pence. Always start on the right.0 + 5 = 5
5 is less than 10, so write 5. There is nothing to carry. - Add the tens of pence. Now the next column to the left.3 + 4 = 7
7 is less than 10, so write 7. There is nothing to carry. - Add the pounds. Now the next column to the left.1 + 2 = 3
3 is less than 10, so write 3. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 1 . 3 0 + £ 2 . 4 5 £ 3 . 7 5
£1.30 + £2.45 = £3.75
Check. Estimate: round to the nearest pound: £1 + £2 = £3. This is close to £3.75. ✓
Watch out. Line up the decimal points. Write £5.00 for a whole number of pounds, so the digits line up.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the amounts in columns with the decimal points lined up. Add the pence first, then the pounds. Carry when a column makes 10 or more.
- Line up the amounts in columns. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 4 . 2 0 + £ 3 . 5 5 £ . - Add the pence. Always start on the right.0 + 5 = 5
5 is less than 10, so write 5. There is nothing to carry. - Add the tens of pence. Now the next column to the left.2 + 5 = 7
7 is less than 10, so write 7. There is nothing to carry. - Add the pounds. Now the next column to the left.4 + 3 = 7
7 is less than 10, so write 7. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 4 . 2 0 + £ 3 . 5 5 £ 7 . 7 5
£4.20 + £3.55 = £7.75
Check. Estimate: round to the nearest pound: £4 + £4 = £8. This is close to £7.75. ✓
Watch out. Line up the decimal points. Write £5.00 for a whole number of pounds, so the digits line up.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the amounts in columns with the decimal points lined up. Add the pence first, then the pounds. Carry when a column makes 10 or more.
- Line up the amounts in columns. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 2 . 7 5 + £ 1 . 2 4 £ . - Add the pence. Always start on the right.5 + 4 = 9
9 is less than 10, so write 9. There is nothing to carry. - Add the tens of pence. Now the next column to the left.7 + 2 = 9
9 is less than 10, so write 9. There is nothing to carry. - Add the pounds. Now the next column to the left.2 + 1 = 3
3 is less than 10, so write 3. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 2 . 7 5 + £ 1 . 2 4 £ 3 . 9 9
£2.75 + £1.24 = £3.99
Check. Estimate: round to the nearest pound: £3 + £1 = £4. This is close to £3.99. ✓
Watch out. Line up the decimal points. Write £5.00 for a whole number of pounds, so the digits line up.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the amounts in columns with the decimal points lined up. Add the pence first, then the pounds. Carry when a column makes 10 or more.
- Line up the amounts in columns. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 5 . 6 0 + £ 2 . 1 0 £ . - Add the pence. Always start on the right.0 + 0 = 0
0 is less than 10, so write 0. There is nothing to carry. - Add the tens of pence. Now the next column to the left.6 + 1 = 7
7 is less than 10, so write 7. There is nothing to carry. - Add the pounds. Now the next column to the left.5 + 2 = 7
7 is less than 10, so write 7. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 5 . 6 0 + £ 2 . 1 0 £ 7 . 7 0
£5.60 + £2.10 = £7.70
Check. Estimate: round to the nearest pound: £6 + £2 = £8. This is close to £7.70. ✓
Watch out. Line up the decimal points. Write £5.00 for a whole number of pounds, so the digits line up.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the amounts in columns with the decimal points lined up. Add the pence first, then the pounds. Carry when a column makes 10 or more.
- Line up the amounts in columns. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 3 . 6 5 + £ 2 . 4 8 £ . - Add the pence. Always start on the right.5 + 8 = 13
13 is 10 or more. Write 3 in the pence column and carry 1 to the tens of pence column. - Add the tens of pence. Now the next column to the left. Add the 1 we carried as well.6 + 4 + 1 = 11
11 is 10 or more. Write 1 in the tens of pence column and carry 1 to the pounds column (across the decimal point). - Add the pounds. Now the next column to the left. Add the 1 we carried as well.3 + 2 + 1 = 6
6 is less than 10, so write 6. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 3 . 6 5 + £ 2 . 4 8 £ 6 . 1 3 1 1
£3.65 + £2.48 = £6.13
Check. Estimate: round to the nearest pound: £4 + £2 = £6. This is close to £6.13. ✓
Watch out. Line up the decimal points. Write £5.00 for a whole number of pounds, so the digits line up.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the amounts in columns with the decimal points lined up. Add the pence first, then the pounds. Carry when a column makes 10 or more.
- Line up the amounts in columns. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 4 . 7 9 + £ 2 . 8 6 £ . - Add the pence. Always start on the right.9 + 6 = 15
15 is 10 or more. Write 5 in the pence column and carry 1 to the tens of pence column. - Add the tens of pence. Now the next column to the left. Add the 1 we carried as well.7 + 8 + 1 = 16
16 is 10 or more. Write 6 in the tens of pence column and carry 1 to the pounds column (across the decimal point). - Add the pounds. Now the next column to the left. Add the 1 we carried as well.4 + 2 + 1 = 7
7 is less than 10, so write 7. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 4 . 7 9 + £ 2 . 8 6 £ 7 . 6 5 1 1
£4.79 + £2.86 = £7.65
Check. Estimate: round to the nearest pound: £5 + £3 = £8. This is close to £7.65. ✓
Watch out. Line up the decimal points. Write £5.00 for a whole number of pounds, so the digits line up.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the amounts in columns with the decimal points lined up. Add the pence first, then the pounds. Carry when a column makes 10 or more.
- Line up the amounts in columns. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 5 . 9 5 + £ 1 . 2 7 £ . - Add the pence. Always start on the right.5 + 7 = 12
12 is 10 or more. Write 2 in the pence column and carry 1 to the tens of pence column. - Add the tens of pence. Now the next column to the left. Add the 1 we carried as well.9 + 2 + 1 = 12
12 is 10 or more. Write 2 in the tens of pence column and carry 1 to the pounds column (across the decimal point). - Add the pounds. Now the next column to the left. Add the 1 we carried as well.5 + 1 + 1 = 7
7 is less than 10, so write 7. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 5 . 9 5 + £ 1 . 2 7 £ 7 . 2 2 1 1
£5.95 + £1.27 = £7.22
Check. Estimate: round to the nearest pound: £6 + £1 = £7. This is close to £7.22. ✓
Watch out. Line up the decimal points. Write £5.00 for a whole number of pounds, so the digits line up.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the amounts in columns with the decimal points lined up. Add the pence first, then the pounds. Carry when a column makes 10 or more.
- Line up the amounts in columns. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 3 . 5 8 + £ 3 . 6 4 £ . - Add the pence. Always start on the right.8 + 4 = 12
12 is 10 or more. Write 2 in the pence column and carry 1 to the tens of pence column. - Add the tens of pence. Now the next column to the left. Add the 1 we carried as well.5 + 6 + 1 = 12
12 is 10 or more. Write 2 in the tens of pence column and carry 1 to the pounds column (across the decimal point). - Add the pounds. Now the next column to the left. Add the 1 we carried as well.3 + 3 + 1 = 7
7 is less than 10, so write 7. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 3 . 5 8 + £ 3 . 6 4 £ 7 . 2 2 1 1
£3.58 + £3.64 = £7.22
Check. Estimate: round to the nearest pound: £4 + £4 = £8. This is close to £7.22. ✓
Watch out. Line up the decimal points. Write £5.00 for a whole number of pounds, so the digits line up.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Add the pounds, then add the pence. If the pence make 100p or more, change 100p into another pound.
- Split each amount into pounds and pence. We add the pounds and the pence separately.£4.65 = £4 + 65p
£2.78 = £2 + 78p - Add the pounds. Add the whole pound parts.£4 + £2 = £6
- Add the pence. Add the pence parts.65p + 78p = 143p
- Change 100 pence into a pound. The pence total is 100p or more. Every 100p is £1.143p = £1 and 43p
£6 + £1 = £7 - Put the pounds and pence together. £7 and 43p = £7.43
Check. Estimate: round to the nearest pound: £5 + £3 = £8. This is close to £7.43. ✓
Watch out. If the pence add up to more than 100p, you must change 100p into £1. Do not write £5.113.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Add the pounds, then add the pence. If the pence make 100p or more, change 100p into another pound.
- Split each amount into pounds and pence. We add the pounds and the pence separately.£5.70 = £5 + 70p
£3.55 = £3 + 55p - Add the pounds. Add the whole pound parts.£5 + £3 = £8
- Add the pence. Add the pence parts.70p + 55p = 125p
- Change 100 pence into a pound. The pence total is 100p or more. Every 100p is £1.125p = £1 and 25p
£8 + £1 = £9 - Put the pounds and pence together. £9 and 25p = £9.25
Check. Estimate: round to the nearest pound: £6 + £4 = £10. This is close to £9.25. ✓
Watch out. If the pence add up to more than 100p, you must change 100p into £1. Do not write £5.113.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Add the pounds, then add the pence. If the pence make 100p or more, change 100p into another pound.
- Split each amount into pounds and pence. We add the pounds and the pence separately.£2.49 = £2 + 49p
£1.98 = £1 + 98p - Add the pounds. Add the whole pound parts.£2 + £1 = £3
- Add the pence. Add the pence parts.49p + 98p = 147p
- Change 100 pence into a pound. The pence total is 100p or more. Every 100p is £1.147p = £1 and 47p
£3 + £1 = £4 - Put the pounds and pence together. £4 and 47p = £4.47
Check. Estimate: round to the nearest pound: £2 + £2 = £4. This is close to £4.47. ✓
Watch out. If the pence add up to more than 100p, you must change 100p into £1. Do not write £5.113.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the bigger amount on top with the decimal points lined up. Subtract the pence first, then the pounds. Exchange if a top digit is too small.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 7 . 8 5 − £ 3 . 4 0 £ . - Subtract the pence. Always start on the right.5 − 0 = 5
- Subtract the tens of pence. Now the next column to the left.8 − 4 = 4
- Subtract the pounds. Now the next column to the left.7 − 3 = 4
- Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 7 . 8 5 − £ 3 . 4 0 £ 4 . 4 5
£7.85 − £3.40 = £4.45
Check. Add back: £4.45 + £3.40 = £7.85. ✓
Estimate: £8 − £3 = £5, close to £4.45.
Watch out. Line up the decimal points and work from the right.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the bigger amount on top with the decimal points lined up. Subtract the pence first, then the pounds. Exchange if a top digit is too small.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 9 . 5 0 − £ 4 . 2 5 £ . - Exchange, then subtract the pence. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
Exchange 1 from the tens of pence column: 5 becomes 4, and the pence column goes from 0 to 10.
10 − 5 = 5 - Subtract the tens of pence. Now the next column to the left.(This digit is 4 now, not 5, because we exchanged from this column.)
4 − 2 = 2 - Subtract the pounds. Now the next column to the left.9 − 4 = 5
- Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 9 . 4 510 0− £ 4 . 2 5 £ 5 . 2 5
£9.50 − £4.25 = £5.25
Check. Add back: £5.25 + £4.25 = £9.50. ✓
Estimate: £10 − £4 = £6, close to £5.25.
Watch out. Take the bottom number from the top number. Exchange 1 pound for 100p when the pence are not enough.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the bigger amount on top with the decimal points lined up. Subtract the pence first, then the pounds. Exchange if a top digit is too small.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 6 . 9 8 − £ 2 . 3 5 £ . - Subtract the pence. Always start on the right.8 − 5 = 3
- Subtract the tens of pence. Now the next column to the left.9 − 3 = 6
- Subtract the pounds. Now the next column to the left.6 − 2 = 4
- Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 6 . 9 8 − £ 2 . 3 5 £ 4 . 6 3
£6.98 − £2.35 = £4.63
Check. Add back: £4.63 + £2.35 = £6.98. ✓
Estimate: £7 − £2 = £5, close to £4.63.
Watch out. Line up the decimal points and work from the right.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the bigger amount on top with the decimal points lined up. Subtract the pence first, then the pounds. Exchange if a top digit is too small.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 8 . 4 0 − £ 5 . 2 0 £ . - Subtract the pence. Always start on the right.0 − 0 = 0
- Subtract the tens of pence. Now the next column to the left.4 − 2 = 2
- Subtract the pounds. Now the next column to the left.8 − 5 = 3
- Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 8 . 4 0 − £ 5 . 2 0 £ 3 . 2 0
£8.40 − £5.20 = £3.20
Check. Add back: £3.20 + £5.20 = £8.40. ✓
Estimate: £8 − £5 = £3, close to £3.20.
Watch out. Line up the decimal points and work from the right.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the bigger amount on top with the decimal points lined up. Subtract the pence first, then the pounds. Exchange if a top digit is too small.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 8 . 2 0 − £ 3 . 6 5 £ . - Exchange, then subtract the pence. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
Exchange 1 from the tens of pence column: 2 becomes 1, and the pence column goes from 0 to 10.
10 − 5 = 5 - Exchange, then subtract the tens of pence. The top digit is smaller than the bottom digit, so we swap 1 from the next column.1 is not enough to take away 6. We need to exchange.
(There were 2 in this column to start with, but we gave one away in an earlier exchange.)
Exchange 1 from the pounds column: 8 becomes 7, and the tens of pence column goes from 1 to 11. (This crosses the decimal point.)
11 − 6 = 5 - Subtract the pounds. Now the next column to the left.(This digit is 7 now, not 8, because we exchanged from this column.)
7 − 3 = 4 - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 7 8. 11 210 0− £ 3 . 6 5 £ 4 . 5 5
£8.20 − £3.65 = £4.55
Check. Add back: £4.55 + £3.65 = £8.20. ✓
Estimate: £8 − £4 = £4, close to £4.55.
Watch out. Take the bottom number from the top number. Exchange 1 pound for 100p when the pence are not enough.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the bigger amount on top with the decimal points lined up. Subtract the pence first, then the pounds. Exchange if a top digit is too small.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 7 . 0 5 − £ 2 . 3 8 £ . - Exchange, then subtract the pence. The top digit is smaller than the bottom digit, so we swap 1 from the next column.5 is not enough to take away 8. We need to exchange.
The columns in between have 0, so we start further left and pass the exchange along one column at a time. Each 0 in the middle becomes 9.
Exchange 1 from the pounds column: 7 becomes 6, and the tens of pence column goes from 0 to 10. (This crosses the decimal point.)
Exchange 1 from the tens of pence column: 10 becomes 9, and the pence column goes from 5 to 15.
15 − 8 = 7 - Subtract the tens of pence. Now the next column to the left.(This digit is 9 now, not 0, because we exchanged from this column.)
9 − 3 = 6 - Subtract the pounds. Now the next column to the left.(This digit is 6 now, not 7, because we exchanged from this column.)
6 − 2 = 4 - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 6 7. 9 015 5− £ 2 . 3 8 £ 4 . 6 7
£7.05 − £2.38 = £4.67
Check. Add back: £4.67 + £2.38 = £7.05. ✓
Estimate: £7 − £2 = £5, close to £4.67.
Watch out. Take the bottom number from the top number. Exchange 1 pound for 100p when the pence are not enough.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the bigger amount on top with the decimal points lined up. Subtract the pence first, then the pounds. Exchange if a top digit is too small.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 6 . 0 0 − £ 2 . 7 5 £ . - Exchange, then subtract the pence. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
The columns in between have 0, so we start further left and pass the exchange along one column at a time. Each 0 in the middle becomes 9.
Exchange 1 from the pounds column: 6 becomes 5, and the tens of pence column goes from 0 to 10. (This crosses the decimal point.)
Exchange 1 from the tens of pence column: 10 becomes 9, and the pence column goes from 0 to 10.
10 − 5 = 5 - Subtract the tens of pence. Now the next column to the left.(This digit is 9 now, not 0, because we exchanged from this column.)
9 − 7 = 2 - Subtract the pounds. Now the next column to the left.(This digit is 5 now, not 6, because we exchanged from this column.)
5 − 2 = 3 - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 5 6. 9 010 0− £ 2 . 7 5 £ 3 . 2 5
£6.00 − £2.75 = £3.25
Check. Add back: £3.25 + £2.75 = £6.00. ✓
Estimate: £6 − £3 = £3, close to £3.25.
Watch out. Take the bottom number from the top number. Exchange 1 pound for 100p when the pence are not enough.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the bigger amount on top with the decimal points lined up. Subtract the pence first, then the pounds. Exchange if a top digit is too small.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£10 £1 10p 1p £ 1 2 . 0 0 − £ 8 . 4 5 £ . - Exchange, then subtract the pence. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
The columns in between have 0, so we start further left and pass the exchange along one column at a time. Each 0 in the middle becomes 9.
Exchange 1 from the pounds column: 2 becomes 1, and the tens of pence column goes from 0 to 10. (This crosses the decimal point.)
Exchange 1 from the tens of pence column: 10 becomes 9, and the pence column goes from 0 to 10.
10 − 5 = 5 - Subtract the tens of pence. Now the next column to the left.(This digit is 9 now, not 0, because we exchanged from this column.)
9 − 4 = 5 - Exchange, then subtract the pounds. The top digit is smaller than the bottom digit, so we swap 1 from the next column.1 is not enough to take away 8. We need to exchange.
(There were 2 in this column to start with, but we gave one away in an earlier exchange.)
Exchange 1 from the tens of pounds column: 1 becomes 0, and the pounds column goes from 1 to 11.
11 − 8 = 3 - Bring down the tens of pounds digit. The bottom number has no digit in this column.(This digit is 0 now, not 1, because we exchanged from this column.)
Nothing to take away here, so the digit stays: 0. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£10 £1 10p 1p £ 0 111 2. 9 010 0− £ 8 . 4 5 £ 3 . 5 5
£12.00 − £8.45 = £3.55
Check. Add back: £3.55 + £8.45 = £12.00. ✓
Estimate: £12 − £8 = £4, close to £3.55.
Watch out. Take the bottom number from the top number. Exchange 1 pound for 100p when the pence are not enough.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the amounts in columns with the decimal points lined up. Add the pence first, then the pounds. Carry when a column makes 10 or more.
- Line up the amounts in columns. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 1 . 4 5 £ 2 . 3 0 + £ 0 . 6 5 £ . - Add the pence. Always start on the right.5 + 0 + 5 = 10
10 is 10 or more. Write 0 in the pence column and carry 1 to the tens of pence column. - Add the tens of pence. Now the next column to the left. Add the 1 we carried as well.4 + 3 + 6 + 1 = 14
14 is 10 or more. Write 4 in the tens of pence column and carry 1 to the pounds column (across the decimal point). - Add the pounds. Now the next column to the left. Add the 1 we carried as well.1 + 2 + 0 + 1 = 4
4 is less than 10, so write 4. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 1 . 4 5 £ 2 . 3 0 + £ 0 . 6 5 £ 4 . 4 0 1 1
£1.45 + £2.30 + £0.65 = £4.40
Check. Estimate: round to the nearest pound: £1 + £2 + £1 = £4. This is close to £4.40. ✓
Watch out. Line up the decimal points. Write £5.00 for a whole number of pounds, so the digits line up.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the amounts in columns with the decimal points lined up. Add the pence first, then the pounds. Carry when a column makes 10 or more.
- Line up the amounts in columns. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 3 . 9 9 £ 2 . 5 0 + £ 1 . 9 9 £ . - Add the pence. Always start on the right.9 + 0 + 9 = 18
18 is 10 or more. Write 8 in the pence column and carry 1 to the tens of pence column. - Add the tens of pence. Now the next column to the left. Add the 1 we carried as well.9 + 5 + 9 + 1 = 24
24 is 10 or more. Write 4 in the tens of pence column and carry 2 to the pounds column (across the decimal point). - Add the pounds. Now the next column to the left. Add the 2 we carried as well.3 + 2 + 1 + 2 = 8
8 is less than 10, so write 8. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 3 . 9 9 £ 2 . 5 0 + £ 1 . 9 9 £ 8 . 4 8 2 1
£3.99 + £2.50 + £1.99 = £8.48
Check. Estimate: round to the nearest pound: £4 + £3 + £2 = £9. This is close to £8.48. ✓
Watch out. Line up the decimal points. Write £5.00 for a whole number of pounds, so the digits line up.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. The missing amount is the difference: take the amount you have from the total.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 7 . 0 0 − £ 4 . 5 0 £ . - Subtract the pence. Always start on the right.0 − 0 = 0
- Exchange, then subtract the tens of pence. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
Exchange 1 from the pounds column: 7 becomes 6, and the tens of pence column goes from 0 to 10. (This crosses the decimal point.)
10 − 5 = 5 - Subtract the pounds. Now the next column to the left.(This digit is 6 now, not 7, because we exchanged from this column.)
6 − 4 = 2 - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 6 7. 10 00 − £ 4 . 5 0 £ 2 . 5 0
£7.00 − £4.50 = £2.50
Check. Add back: £2.50 + £4.50 = £7.00. ✓
Estimate: £7 − £5 = £2, close to £2.50.
Watch out. Take the bottom number from the top number. Exchange 1 pound for 100p when the pence are not enough.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. The missing amount is the difference: take the amount you have from the total.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£10 £1 10p 1p £ 1 0 . 0 0 − £ 6 . 7 5 £ . - Exchange, then subtract the pence. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
The columns in between have 0, so we start further left and pass the exchange along one column at a time. Each 0 in the middle becomes 9.
Exchange 1 from the tens of pounds column: 1 becomes 0, and the pounds column goes from 0 to 10.
Exchange 1 from the pounds column: 10 becomes 9, and the tens of pence column goes from 0 to 10. (This crosses the decimal point.)
Exchange 1 from the tens of pence column: 10 becomes 9, and the pence column goes from 0 to 10.
10 − 5 = 5 - Subtract the tens of pence. Now the next column to the left.(This digit is 9 now, not 0, because we exchanged from this column.)
9 − 7 = 2 - Subtract the pounds. Now the next column to the left.(This digit is 9 now, not 0, because we exchanged from this column.)
9 − 6 = 3 - Bring down the tens of pounds digit. The bottom number has no digit in this column.(This digit is 0 now, not 1, because we exchanged from this column.)
Nothing to take away here, so the digit stays: 0. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£10 £1 10p 1p £ 0 19 0. 9 010 0− £ 6 . 7 5 £ 3 . 2 5
£10.00 − £6.75 = £3.25
Check. Add back: £3.25 + £6.75 = £10.00. ✓
Estimate: £10 − £7 = £3, close to £3.25.
Watch out. Take the bottom number from the top number. Exchange 1 pound for 100p when the pence are not enough.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. The missing amount is the difference: take the amount you have from the total.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 5 . 0 0 − £ 3 . 6 5 £ . - Exchange, then subtract the pence. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
The columns in between have 0, so we start further left and pass the exchange along one column at a time. Each 0 in the middle becomes 9.
Exchange 1 from the pounds column: 5 becomes 4, and the tens of pence column goes from 0 to 10. (This crosses the decimal point.)
Exchange 1 from the tens of pence column: 10 becomes 9, and the pence column goes from 0 to 10.
10 − 5 = 5 - Subtract the tens of pence. Now the next column to the left.(This digit is 9 now, not 0, because we exchanged from this column.)
9 − 6 = 3 - Subtract the pounds. Now the next column to the left.(This digit is 4 now, not 5, because we exchanged from this column.)
4 − 3 = 1 - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 4 5. 9 010 0− £ 3 . 6 5 £ 1 . 3 5
£5.00 − £3.65 = £1.35
Check. Add back: £1.35 + £3.65 = £5.00. ✓
Estimate: £5 − £4 = £1, close to £1.35.
Watch out. Take the bottom number from the top number. Exchange 1 pound for 100p when the pence are not enough.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. The missing amount is the difference: take the amount you have from the total.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£10 £1 10p 1p £ 1 2 . 0 0 − £ 8 . 4 5 £ . - Exchange, then subtract the pence. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
The columns in between have 0, so we start further left and pass the exchange along one column at a time. Each 0 in the middle becomes 9.
Exchange 1 from the pounds column: 2 becomes 1, and the tens of pence column goes from 0 to 10. (This crosses the decimal point.)
Exchange 1 from the tens of pence column: 10 becomes 9, and the pence column goes from 0 to 10.
10 − 5 = 5 - Subtract the tens of pence. Now the next column to the left.(This digit is 9 now, not 0, because we exchanged from this column.)
9 − 4 = 5 - Exchange, then subtract the pounds. The top digit is smaller than the bottom digit, so we swap 1 from the next column.1 is not enough to take away 8. We need to exchange.
(There were 2 in this column to start with, but we gave one away in an earlier exchange.)
Exchange 1 from the tens of pounds column: 1 becomes 0, and the pounds column goes from 1 to 11.
11 − 8 = 3 - Bring down the tens of pounds digit. The bottom number has no digit in this column.(This digit is 0 now, not 1, because we exchanged from this column.)
Nothing to take away here, so the digit stays: 0. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£10 £1 10p 1p £ 0 111 2. 9 010 0− £ 8 . 4 5 £ 3 . 5 5
£12.00 − £8.45 = £3.55
Check. Add back: £3.55 + £8.45 = £12.00. ✓
Estimate: £12 − £8 = £4, close to £3.55.
Watch out. Take the bottom number from the top number. Exchange 1 pound for 100p when the pence are not enough.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Add up the cost of everything. Then take the total cost away from the money that was paid. What is left is the change.
- Draw a bar model. The whole bar is the money we pay with. It is split into the cost of what we buy and the change.
- Step 1: find the change. Take the cost away from the money paid.£5.00 − £3.65 = £1.35
£1 10p 1p £ 4 5. 9 010 0− £ 3 . 6 5 £ 1 . 3 5 - Write the answer. The change is £1.35
Check. Add the change to the cost: £3.65 + £1.35 = £5.00, the money paid. ✓
Watch out. Take the cost away from the money paid, not the other way round.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Add up the cost of everything. Then take the total cost away from the money that was paid. What is left is the change.
- Draw a bar model. The whole bar is the money we pay with. It is split into the cost of what we buy and the change.
- Step 1: find the change. Take the cost away from the money paid.£10.00 − £7.45 = £2.55
£10 £1 10p 1p £ 0 19 0. 9 010 0− £ 7 . 4 5 £ 2 . 5 5 - Write the answer. The change is £2.55
Check. Add the change to the cost: £7.45 + £2.55 = £10.00, the money paid. ✓
Watch out. Take the cost away from the money paid, not the other way round.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Add up the cost of everything. Then take the total cost away from the money that was paid. What is left is the change.
- Draw a bar model. The whole bar is the money we pay with. It is split into the cost of what we buy and the change.
- Step 1: find the change. Take the cost away from the money paid.£20.00 − £12.50 = £7.50
£10 £1 10p 1p £ 1 29 0. 10 00 − £ 1 2 . 5 0 £ 7 . 5 0 - Write the answer. The change is £7.50
Check. Add the change to the cost: £12.50 + £7.50 = £20.00, the money paid. ✓
Watch out. Take the cost away from the money paid, not the other way round.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Add up the cost of everything. Then take the total cost away from the money that was paid. What is left is the change.
- Draw a bar model. The whole bar is the money we pay with. It is split into the cost of what we buy and the change.
- Step 1: find the change. Take the cost away from the money paid.£5.00 − £1.99 = £3.01
£1 10p 1p £ 4 5. 9 010 0− £ 1 . 9 9 £ 3 . 0 1 - Write the answer. The change is £3.01
Check. Add the change to the cost: £1.99 + £3.01 = £5.00, the money paid. ✓
Watch out. Take the cost away from the money paid, not the other way round.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Add up the cost of everything. Then take the total cost away from the money that was paid. What is left is the change.
- Draw a bar model. The whole bar is the money we pay with. It is split into the cost of what we buy and the change.
- Step 1: find the total cost. Add all the prices.£2.85 + £0.95 = £3.80
£1 10p 1p £ 2 . 8 5 + £ 0 . 9 5 £ 3 . 8 0 1 1 - Step 2: find the change. Take the cost away from the money paid.£10.00 − £3.80 = £6.20
£10 £1 10p 1p £ 0 19 0. 10 00 − £ 3 . 8 0 £ 6 . 2 0 - Write the answer. The change is £6.20
Check. Add the change to the cost: £3.80 + £6.20 = £10.00, the money paid. ✓
Watch out. Take away the TOTAL cost, not just one price.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Add up the cost of everything. Then take the total cost away from the money that was paid. What is left is the change.
- Draw a bar model. The whole bar is the money we pay with. It is split into the cost of what we buy and the change.
- Step 1: find the total cost. Add all the prices.£4.50 + £6.75 = £11.25
£10 £1 10p 1p £ 4 . 5 0 + £ 6 . 7 5 £ 1 1 . 2 5 1 1 - Step 2: find the change. Take the cost away from the money paid.£12.00 − £11.25 = £0.75
£10 £1 10p 1p £ 1 1 2. 9 010 0− £ 1 1 . 2 5 £ 0 . 7 5 - Write the answer. The change is £0.75
Check. Add the change to the cost: £11.25 + £0.75 = £12.00, the money paid. ✓
Watch out. Take away the TOTAL cost, not just one price.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Round each price to the nearest pound. Then add.
- Round each price. 50p or more rounds up to the next pound. Less than 50p rounds down.£3.95 ≈ £4 (95p rounds up)
£2.10 ≈ £2 (10p rounds down) - Add the rounded prices. £4 + £2 = £6
Check. The exact total is a bit more than this. ✓
Watch out. Round each amount first, then add.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the amounts in columns with the decimal points lined up. Add the pence first, then the pounds. Carry when a column makes 10 or more.
- Line up the amounts in columns. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 3 . 9 5 + £ 2 . 1 0 £ . - Add the pence. Always start on the right.5 + 0 = 5
5 is less than 10, so write 5. There is nothing to carry. - Add the tens of pence. Now the next column to the left.9 + 1 = 10
10 is 10 or more. Write 0 in the tens of pence column and carry 1 to the pounds column (across the decimal point). - Add the pounds. Now the next column to the left. Add the 1 we carried as well.3 + 2 + 1 = 6
6 is less than 10, so write 6. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 3 . 9 5 + £ 2 . 1 0 £ 6 . 0 5 1
£3.95 + £2.10 = £6.05
Check. Estimate: round to the nearest pound: £4 + £2 = £6. This is close to £6.05. ✓
Watch out. Line up the decimal points. Write £5.00 for a whole number of pounds, so the digits line up.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Subtract the estimate from the exact total to see how close they are.
- Line up the amounts in columns. The bigger amount goes on top. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 6 . 0 5 − £ 6 . 0 0 £ . - Subtract the pence. Always start on the right.5 − 0 = 5
- Subtract the tens of pence. Now the next column to the left.0 − 0 = 0
- Subtract the pounds. Now the next column to the left.6 − 6 = 0
- Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 6 . 0 5 − £ 6 . 0 0 £ 0 . 0 5
£6.05 − £6.00 = £0.05
Check. Add back: £0.05 + £6.00 = £6.05. ✓
Estimate: £6 − £6 = £0, close to £0.05.
Watch out. Line up the decimal points and work from the right.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Add the pounds and add the pence again. Check whether the pence are more than 100p.
- Look at what Jack did. Jack added the pounds and added the pence.£3 + £2 = £5 and 65p + 48p = 113p, so Jack wrote £5.113.
- Find the mistake. 113p is more than 100p. Only two digits can go after the decimal point, so 100p must be changed into £1.113p = £1 and 13p
- Work out the correct answer. Add the extra pound to the pounds.£5 + £1 = £6, so the total is £6.13
Check. Estimate: £4 + £2 = £6, so £6.13 is sensible and £5.113 is not. ✓
Watch out. Money has only two digits after the decimal point. If the pence reach 100 or more, change 100p into £1.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Add every possible pair of prices. Look for the pair that makes exactly £5.
- List every pair. There are 5 prices, so there are 10 different pairs. Work through them in order.£1.35 + £2.20 = £3.55
£1.35 + £2.80 = £4.15
£1.35 + £3.15 = £4.50
£1.35 + £1.95 = £3.30
£2.20 + £2.80 = £5.00 ✓
£2.20 + £3.15 = £5.35
£2.20 + £1.95 = £4.15
£2.80 + £3.15 = £5.95
£2.80 + £1.95 = £4.75
£3.15 + £1.95 = £5.10 - Find the pair that makes £5.00. Only one total is exactly £5.00.£2.20 and £2.80
Check. £2.20 + £2.80 = £5.00. ✓
Watch out. Look at the pence first: 20p + 80p = 100p makes the pence a whole pound. It saves time.
Exercise 6H Multiplying, sharing and measures
Non-calculatorKey words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Multiply the pounds and the pence separately. Change any pence over 100p into pounds. Then add the parts.
- Split the price into pounds and pence. It is easier to multiply each part.£1.20 = £1 + 20p
- Multiply the pounds. 3 lots of £1.£1 × 3 = £3
- Multiply the pence. 3 lots of 20p.20p × 3 = 60p
- Add the parts together. £3 + £0.60 = £3.60
Check. Estimate: £1.20 is about £1, and 3 × £1 = £3, close to £3.60. ✓
Watch out. Write the answer with two decimal places, and change pence over 100p into pounds.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Multiply the pounds and the pence separately. Change any pence over 100p into pounds. Then add the parts.
- Split the price into pounds and pence. It is easier to multiply each part.£2.50 = £2 + 50p
- Multiply the pounds. 4 lots of £2.£2 × 4 = £8
- Multiply the pence. 4 lots of 50p.50p × 4 = 200p
- Change the pence into pounds. 100p = £1.200p = £2 and 0p = £2.00
- Add the parts together. £8 + £2.00 = £10.00
Check. Estimate: £2.50 is about £3, and 4 × £3 = £12, close to £10.00. ✓
Watch out. Write the answer with two decimal places, and change pence over 100p into pounds.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Multiply the pounds and the pence separately. Change any pence over 100p into pounds. Then add the parts.
- Split the price into pounds and pence. It is easier to multiply each part.£3.45 = £3 + 45p
- Multiply the pounds. 2 lots of £3.£3 × 2 = £6
- Multiply the pence. 2 lots of 45p.45p × 2 = 90p
- Add the parts together. £6 + £0.90 = £6.90
Check. Estimate: £3.45 is about £3, and 2 × £3 = £6, close to £6.90. ✓
Watch out. Write the answer with two decimal places, and change pence over 100p into pounds.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Multiply the pounds and the pence separately. Change any pence over 100p into pounds. Then add the parts.
- Multiply the pence. 5 lots of 65p.65p × 5 = 325p
- Change the pence into pounds. 100p = £1.325p = £3 and 25p = £3.25
- Add the parts together. 325p = £3.25
Check. Estimate: £0.65 is about £1, and 5 × £1 = £5, close to £3.25. ✓
Watch out. Write the answer with two decimal places, and change pence over 100p into pounds.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change the money into pence. Divide by the number of shares. Change the answer back to pounds and pence.
- Change the amount to pence. Pence are whole numbers, so they are easier to divide.£6.80 = 680p
- Divide by 2. Sharing equally into 2 means dividing by 2.680p ÷ 2 = 340p
- Change back to pounds and pence. 100p = £1.340p = £3.40
Check. Go back: £3.40 × 2 = £6.80. ✓
Watch out. Do not divide the pounds and pence as if they were one number. Change to pence first.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change the money into pence. Divide by the number of shares. Change the answer back to pounds and pence.
- Change the amount to pence. Pence are whole numbers, so they are easier to divide.£9.60 = 960p
- Divide by 4. Sharing equally into 4 means dividing by 4.960p ÷ 4 = 240p
- Change back to pounds and pence. 100p = £1.240p = £2.40
Check. Go back: £2.40 × 4 = £9.60. ✓
Watch out. Do not divide the pounds and pence as if they were one number. Change to pence first.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change the money into pence. Divide by the number of shares. Change the answer back to pounds and pence.
- Change the amount to pence. Pence are whole numbers, so they are easier to divide.£8.40 = 840p
- Divide by 3. Sharing equally into 3 means dividing by 3.840p ÷ 3 = 280p
- Change back to pounds and pence. 100p = £1.280p = £2.80
Check. Go back: £2.80 × 3 = £8.40. ✓
Watch out. Do not divide the pounds and pence as if they were one number. Change to pence first.
Key words. Pence (p) are small amounts of money. 100 pence make 1 pound.
Method. Change the money into pence. Find a fraction of it: divide by the bottom number, then multiply by the top number. Change back to pounds.
- Change the pounds into pence. 1 pound is 100 pence, so we can divide the pence exactly.£8 = 8 × 100 = 800p
- Find one part: divide by the bottom number, 2. The bottom number says how many equal parts.800p ÷ 2 = 400p
- Change back to pounds and pence. 100p = £1, so divide by 100. Always show two decimal places.400p = £4.00
Check. 400p × 2 = 800p, so 2 parts make the whole amount. ✓
Watch out. Write money with two decimal places: £3.50, not £3.5.
Key words. Pence (p) are small amounts of money. 100 pence make 1 pound.
Method. Change the money into pence. Find a fraction of it: divide by the bottom number, then multiply by the top number. Change back to pounds.
- Change the pounds into pence. 1 pound is 100 pence, so we can divide the pence exactly.£10 = 10 × 100 = 1000p
- Find one part: divide by the bottom number, 4. The bottom number says how many equal parts.1000p ÷ 4 = 250p
- Change back to pounds and pence. 100p = £1, so divide by 100. Always show two decimal places.250p = £2.50
Check. 250p × 4 = 1000p, so 4 parts make the whole amount. ✓
Watch out. Write money with two decimal places: £3.50, not £3.5.
Key words. Pence (p) are small amounts of money. 100 pence make 1 pound.
Method. Change the money into pence. Find a fraction of it: divide by the bottom number, then multiply by the top number. Change back to pounds.
- Change the pounds into pence. 1 pound is 100 pence, so we can divide the pence exactly.£6 = 6 × 100 = 600p
- Find one part: divide by the bottom number, 4. The bottom number says how many equal parts.600p ÷ 4 = 150p
- Multiply by the top number, 3. The top number says how many parts we take.150p × 3 = 450p
- Change back to pounds and pence. 100p = £1, so divide by 100. Always show two decimal places.450p = £4.50
Check. 150p × 4 = 600p, so 4 parts make the whole amount. ✓
Watch out. Write money with two decimal places: £3.50, not £3.5.
Key words. Lengths, masses and capacities can be written as decimals: 2.5 m is two and a half metres, 1.75 kg is 1 and 3/4 kilograms. Line up the decimal points to add or subtract.
Method. Line up the decimal points. Add column by column from the right. Carry when a column makes 10 or more. Write the unit.
- Give both numbers the same number of decimal places. Adding a 0 on the end of a decimal does not change its value. It helps the digits line up.1.5 = 1.50
- Line up the amounts in columns. Put the decimal points in a straight line, so tenths are under tenths and ones under ones.
O t h 1 . 5 0 + 2 . 2 5 . - Add the hundredths. Always start on the right.0 + 5 = 5
5 is less than 10, so write 5. There is nothing to carry. - Add the tenths. Now the next column to the left.5 + 2 = 7
7 is less than 10, so write 7. There is nothing to carry. - Add the ones. Now the next column to the left.1 + 2 = 3
3 is less than 10, so write 3. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
O t h 1 . 5 0 + 2 . 2 5 3 . 7 5
1.50 kg + 2.25 kg = 3.75 kg
Check. Take away: 3.75 kg − 2.25 kg = 1.50 kg. ✓
Watch out. Line up the decimal points, not the right-hand digits: 2.5 has fewer digits than 1.75, so write 2.50.
Key words. Lengths, masses and capacities can be written as decimals: 2.5 m is two and a half metres, 1.75 kg is 1 and 3/4 kilograms. Line up the decimal points to add or subtract.
Method. Line up the decimal points. Add column by column from the right. Carry when a column makes 10 or more. Write the unit.
- Give both numbers the same number of decimal places. Adding a 0 on the end of a decimal does not change its value. It helps the digits line up.1.5 = 1.50
- Line up the amounts in columns. Put the decimal points in a straight line, so tenths are under tenths and ones under ones.
O t h 0 . 7 5 + 1 . 5 0 . - Add the hundredths. Always start on the right.5 + 0 = 5
5 is less than 10, so write 5. There is nothing to carry. - Add the tenths. Now the next column to the left.7 + 5 = 12
12 is 10 or more. Write 2 in the tenths column and carry 1 to the ones column (across the decimal point). - Add the ones. Now the next column to the left. Add the 1 we carried as well.0 + 1 + 1 = 2
2 is less than 10, so write 2. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
O t h 0 . 7 5 + 1 . 5 0 2 . 2 5 1
0.75 m + 1.50 m = 2.25 m
Check. Take away: 2.25 m − 1.50 m = 0.75 m. ✓
Watch out. Line up the decimal points, not the right-hand digits: 2.5 has fewer digits than 1.75, so write 2.50.
Key words. Lengths, masses and capacities can be written as decimals: 2.5 m is two and a half metres, 1.75 kg is 1 and 3/4 kilograms. Line up the decimal points to add or subtract.
Method. Line up the decimal points. Add column by column from the right. Carry when a column makes 10 or more. Write the unit.
- Give both numbers the same number of decimal places. Adding a 0 on the end of a decimal does not change its value. It helps the digits line up.2.4 = 2.40
- Line up the amounts in columns. Put the decimal points in a straight line, so tenths are under tenths and ones under ones.
O t h 2 . 4 0 + 1 . 3 5 . - Add the hundredths. Always start on the right.0 + 5 = 5
5 is less than 10, so write 5. There is nothing to carry. - Add the tenths. Now the next column to the left.4 + 3 = 7
7 is less than 10, so write 7. There is nothing to carry. - Add the ones. Now the next column to the left.2 + 1 = 3
3 is less than 10, so write 3. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
O t h 2 . 4 0 + 1 . 3 5 3 . 7 5
2.40 litres + 1.35 litres = 3.75 litres
Check. Take away: 3.75 litres − 1.35 litres = 2.40 litres. ✓
Watch out. Line up the decimal points, not the right-hand digits: 2.5 has fewer digits than 1.75, so write 2.50.
Key words. Lengths, masses and capacities can be written as decimals: 2.5 m is two and a half metres, 1.75 kg is 1 and 3/4 kilograms. Line up the decimal points to add or subtract.
Method. Line up the decimal points with the bigger number on top. Subtract column by column from the right. Exchange when a top digit is too small. Write the unit.
- Give both numbers the same number of decimal places. Adding a 0 on the end of a decimal does not change its value. It helps the digits line up.4.5 = 4.50
- Line up the amounts in columns. The bigger number goes on top. Put the decimal points in a straight line.
O t h 4 . 5 0 − 1 . 2 5 . - Exchange, then subtract the hundredths. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
Exchange 1 from the tenths column: 5 becomes 4, and the hundredths column goes from 0 to 10.
10 − 5 = 5 - Subtract the tenths. Now the next column to the left.(This digit is 4 now, not 5, because we exchanged from this column.)
4 − 2 = 2 - Subtract the ones. Now the next column to the left.4 − 1 = 3
- Read the answer. Put the decimal point in the answer, directly under the other decimal points.
O t h 4 . 4 510 0− 1 . 2 5 3 . 2 5
4.50 m − 1.25 m = 3.25 m
Check. Add back: 3.25 m + 1.25 m = 4.50 m. ✓
Watch out. Line up the decimal points, not the right-hand digits: 2.5 has fewer digits than 1.75, so write 2.50.
Key words. Lengths, masses and capacities can be written as decimals: 2.5 m is two and a half metres, 1.75 kg is 1 and 3/4 kilograms. Line up the decimal points to add or subtract.
Method. Line up the decimal points with the bigger number on top. Subtract column by column from the right. Exchange when a top digit is too small. Write the unit.
- Give both numbers the same number of decimal places. Adding a 0 on the end of a decimal does not change its value. It helps the digits line up.5 = 5.00
- Line up the amounts in columns. The bigger number goes on top. Put the decimal points in a straight line.
O t h 5 . 0 0 − 2 . 7 5 . - Exchange, then subtract the hundredths. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
The columns in between have 0, so we start further left and pass the exchange along one column at a time. Each 0 in the middle becomes 9.
Exchange 1 from the ones column: 5 becomes 4, and the tenths column goes from 0 to 10. (This crosses the decimal point.)
Exchange 1 from the tenths column: 10 becomes 9, and the hundredths column goes from 0 to 10.
10 − 5 = 5 - Subtract the tenths. Now the next column to the left.(This digit is 9 now, not 0, because we exchanged from this column.)
9 − 7 = 2 - Subtract the ones. Now the next column to the left.(This digit is 4 now, not 5, because we exchanged from this column.)
4 − 2 = 2 - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
O t h 4 5. 9 010 0− 2 . 7 5 2 . 2 5
5.00 kg − 2.75 kg = 2.25 kg
Check. Add back: 2.25 kg + 2.75 kg = 5.00 kg. ✓
Watch out. Line up the decimal points, not the right-hand digits: 2.5 has fewer digits than 1.75, so write 2.50.
Key words. Lengths, masses and capacities can be written as decimals: 2.5 m is two and a half metres, 1.75 kg is 1 and 3/4 kilograms. Line up the decimal points to add or subtract.
Method. Line up the decimal points with the bigger number on top. Subtract column by column from the right. Exchange when a top digit is too small. Write the unit.
- Give both numbers the same number of decimal places. Adding a 0 on the end of a decimal does not change its value. It helps the digits line up.2.1 = 2.10
- Line up the amounts in columns. The bigger number goes on top. Put the decimal points in a straight line.
O t h 2 . 1 0 − 0 . 8 5 . - Exchange, then subtract the hundredths. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
Exchange 1 from the tenths column: 1 becomes 0, and the hundredths column goes from 0 to 10.
10 − 5 = 5 - Exchange, then subtract the tenths. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 8. We need to exchange.
(There were 1 in this column to start with, but we gave one away in an earlier exchange.)
Exchange 1 from the ones column: 2 becomes 1, and the tenths column goes from 0 to 10. (This crosses the decimal point.)
10 − 8 = 2 - Subtract the ones. Now the next column to the left.(This digit is 1 now, not 2, because we exchanged from this column.)
1 − 0 = 1 - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
O t h 1 2. 10 110 0− 0 . 8 5 1 . 2 5
2.10 litres − 0.85 litres = 1.25 litres
Check. Add back: 1.25 litres + 0.85 litres = 2.10 litres. ✓
Watch out. Line up the decimal points, not the right-hand digits: 2.5 has fewer digits than 1.75, so write 2.50.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Find the cost of each group of items. Add them to find the total. Then take the total away from the money paid to find the change.
- Find the cost of 4 stickers. 4 lots of £0.35.4 × £0.35 = £1.40 (35p × 4 = 140p)
- Add the costs to find the total. Use a column method, with the decimal points lined up.£1.40 + £2.20 = £3.60
£1 10p 1p £ 1 . 4 0 + £ 2 . 2 0 £ 3 . 6 0 - Take the total cost away from the money paid. What is left is the change.£5.00 − £3.60 = £1.40
£1 10p 1p £ 4 5. 10 00 − £ 3 . 6 0 £ 1 . 4 0 - Write the answer. The change is £1.40
Check. Add the change to the total: £3.60 + £1.40 = £5.00. ✓
Watch out. Multiply first, then add, then subtract from the money paid.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Find the cost of each group of items. Then add the costs together.
- Find the cost of 4 tickets. 4 lots of £4.75.4 × £4.75 = £19.00 (£16 + 300p)
- Write the answer. The total is £19.00
Check. Estimate: £19 = £19, close to £19.00. ✓
Watch out. Multiply first when there is more than one of an item, then add.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Find how much more money is needed. Then find how many weeks of saving give that amount.
- Find how much more money is needed. Take the money already saved away from the cost.£12.60 − £4.20 = £8.40
- Find how many weeks it takes. Each week adds £2.10. We ask how many lots of £2.10 make £8.40. Change to pence to divide.840p ÷ 210p = 4 weeks
- Write the answer. 4 weeks
Check. 4 × £2.10 = £8.40, and £4.20 + £8.40 = £12.60. ✓
Watch out. First find what is still needed. Do not divide the whole price.
Key words. Lengths, masses and capacities can be written as decimals: 2.5 m is two and a half metres, 1.75 kg is 1 and 3/4 kilograms. Line up the decimal points to add or subtract.
Method. Line up the decimal points. Add column by column from the right. Carry when a column makes 10 or more. Write the unit.
- Give both numbers the same number of decimal places. Adding a 0 on the end of a decimal does not change its value. It helps the digits line up.2.5 = 2.50
- Line up the amounts in columns. Put the decimal points in a straight line, so tenths are under tenths and ones under ones.
O t h 1 . 7 5 + 2 . 5 0 . - Add the hundredths. Always start on the right.5 + 0 = 5
5 is less than 10, so write 5. There is nothing to carry. - Add the tenths. Now the next column to the left.7 + 5 = 12
12 is 10 or more. Write 2 in the tenths column and carry 1 to the ones column (across the decimal point). - Add the ones. Now the next column to the left. Add the 1 we carried as well.1 + 2 + 1 = 4
4 is less than 10, so write 4. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
O t h 1 . 7 5 + 2 . 5 0 4 . 2 5 1
1.75 m + 2.50 m = 4.25 m
Check. Take away: 4.25 m − 2.50 m = 1.75 m. ✓
Watch out. Line up the decimal points, not the right-hand digits: 2.5 has fewer digits than 1.75, so write 2.50.
Key words. Lengths, masses and capacities can be written as decimals: 2.5 m is two and a half metres, 1.75 kg is 1 and 3/4 kilograms. Line up the decimal points to add or subtract.
Method. Line up the decimal points with the bigger number on top. Subtract column by column from the right. Exchange when a top digit is too small. Write the unit.
- Give both numbers the same number of decimal places. Adding a 0 on the end of a decimal does not change its value. It helps the digits line up.5 = 5.00
- Line up the amounts in columns. The bigger number goes on top. Put the decimal points in a straight line.
O t h 5 . 0 0 − 4 . 2 5 . - Exchange, then subtract the hundredths. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
The columns in between have 0, so we start further left and pass the exchange along one column at a time. Each 0 in the middle becomes 9.
Exchange 1 from the ones column: 5 becomes 4, and the tenths column goes from 0 to 10. (This crosses the decimal point.)
Exchange 1 from the tenths column: 10 becomes 9, and the hundredths column goes from 0 to 10.
10 − 5 = 5 - Subtract the tenths. Now the next column to the left.(This digit is 9 now, not 0, because we exchanged from this column.)
9 − 2 = 7 - Subtract the ones. Now the next column to the left.(This digit is 4 now, not 5, because we exchanged from this column.)
4 − 4 = 0 - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
O t h 4 5. 9 010 0− 4 . 2 5 0 . 7 5
5.00 m − 4.25 m = 0.75 m
Check. Add back: 0.75 m + 4.25 m = 5.00 m. ✓
Watch out. Line up the decimal points, not the right-hand digits: 2.5 has fewer digits than 1.75, so write 2.50.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Change the money into pence. Divide by the number of shares. Change the answer back to pounds and pence.
- Change the amount to pence. Pence are whole numbers, so they are easier to divide.£9.60 = 960p
- Divide by 4. Sharing equally into 4 means dividing by 4.960p ÷ 4 = 240p
- Change back to pounds and pence. 100p = £1.240p = £2.40
Check. Go back: £2.40 × 4 = £9.60. ✓
Watch out. Do not divide the pounds and pence as if they were one number. Change to pence first.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Write the amounts in columns with the decimal points lined up. Add the pence first, then the pounds. Carry when a column makes 10 or more.
- Line up the amounts in columns. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 2 . 4 0 + £ 1 . 3 5 £ . - Add the pence. Always start on the right.0 + 5 = 5
5 is less than 10, so write 5. There is nothing to carry. - Add the tens of pence. Now the next column to the left.4 + 3 = 7
7 is less than 10, so write 7. There is nothing to carry. - Add the pounds. Now the next column to the left.2 + 1 = 3
3 is less than 10, so write 3. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 2 . 4 0 + £ 1 . 3 5 £ 3 . 7 5
£2.40 + £1.35 = £3.75
Check. Estimate: round to the nearest pound: £2 + £1 = £3. This is close to £3.75. ✓
Watch out. Line up the decimal points. Write £5.00 for a whole number of pounds, so the digits line up.
Key words. In column addition and column subtraction you write the numbers one under the other with the decimal points in a straight line, and work one column at a time from the right. To carry is to move 10 of one column to the next column. To exchange is to swap 1 of the next column for 10 of this one.
Method. Add the three prices to find the total. Then compare the total with £10.
- Line up the amounts in columns. Pounds under pounds and pence under pence, with the decimal points in a straight line.
£1 10p 1p £ 2 . 9 5 £ 3 . 2 0 + £ 3 . 5 5 £ . - Add the pence. Always start on the right.5 + 0 + 5 = 10
10 is 10 or more. Write 0 in the pence column and carry 1 to the tens of pence column. - Add the tens of pence. Now the next column to the left. Add the 1 we carried as well.9 + 2 + 5 + 1 = 17
17 is 10 or more. Write 7 in the tens of pence column and carry 1 to the pounds column (across the decimal point). - Add the pounds. Now the next column to the left. Add the 1 we carried as well.2 + 3 + 3 + 1 = 9
9 is less than 10, so write 9. There is nothing to carry. - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
£1 10p 1p £ 2 . 9 5 £ 3 . 2 0 + £ 3 . 5 5 £ 9 . 7 0 1 1
£2.95 + £3.20 + £3.55 = £9.70 - Compare the total with £10. The total must not be more than the money she has.£9.70 is less than £10.00, so yes. She has £0.30 left.
Check. Estimate: £3 + £3 + £4 = £10, and the exact total is a little less. ✓
Watch out. Line up the decimal points and carry the pence into the pounds.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Try every way to split the coins into the two kinds. Work out the total of each way and look for the one that matches.
- List every possible way. There are 7 coins altogether. If there are 0, 1, 2 ... 50p coins, the rest are 20p coins.
- Work out the total for each way. Multiply each number of coins by its value, then add.
50p coins 20p coins Total 0 7 140p 1 6 170p 2 5 200p 3 4 230p 4 3 260p 5 2 290p 6 1 320p 7 0 350p - Find the total 260p. Only one row matches.4 coins of 50p and 3 coins of 20p
Check. 4 × 50p + 3 × 20p = 200p + 60p = 260p = £2.60. ✓
Watch out. Work in pence and be systematic: start with 0 of one coin and count up.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Work out the cost again, step by step, and compare with Leo’s answer.
- Look at what Leo did. Leo multiplied the pounds (3 × £1 = £3) and the pence (3 × 45p = 135p). Then he wrote the pence after the point.He wrote £3.135.
- Find the mistake. 135p is more than 100p. Only two digits can go after the decimal point, so 100p must be changed into £1.135p = £1 and 35p
- Work out the correct answer. Add the extra pound to the 3 pounds.£3 + £1.35 = £4.35
Check. Estimate: 3 × £1.45 is about 3 × £1 = £3, and a bit more: £4.35 is sensible but £3.135 is not. ✓
Watch out. Pence over 99 must be changed into pounds.
Chapter summary
| Skill | Method |
|---|---|
| Tenths | 1/10 = 0.1. The first digit after the decimal point is tenths. 7/10 = 0.7. 10 tenths = 1 whole: 0.9 + 0.1 = 1.0. 2 4/10 = 2.4. |
| Hundredths | 1/100 = 0.01. The second digit after the point is hundredths. 37/100 = 0.37. 10 hundredths = 1 tenth. Use a 0 to keep the place: 7/100 = 0.07. |
| Fractions ↔ decimals | Tenths: count one digit after the point (bottom number 10). Hundredths: two digits (bottom number 100). 0.63 = 63/100, 2.3 = 2 3/10. |
| Place value | Ones . tenths hundredths. In 3.45: 3 ones, 4 tenths (0.4), 5 hundredths (0.05). 3.45 = 3 + 0.4 + 0.05. |
| Counting | Count in 0.1 or 0.01. 0.8, 0.9, 1.0, 1.1. 0.08, 0.09, 0.10, 0.11. Keep the same number of decimal places. |
| Halves and quarters | 1/2 = 0.5, 1/4 = 0.25, 3/4 = 0.75 (50, 25 and 75 squares of a hundred square). 2 1/2 = 2.5. |
| Dividing by 10 and 100 | ÷ 10: digits move 1 column right. ÷ 100: digits move 2 columns right. Fill empty columns with 0: 7 ÷ 100 = 0.07. |
| Comparing and ordering | Line up the decimal points. Compare from the left: ones, tenths, hundredths. 0.45 < 0.5 (45 hundredths < 50 hundredths). |
| Rounding to a whole number | Look at the tenths digit. 5 or more: round up. 4 or less: round down. 3.4 ≈ 3, 3.5 ≈ 4, 3.7 ≈ 4. |
| Pounds and pence | 100p = £1. Money has two digits after the point: £3.05. Pence to pounds: ÷ 100. Pounds to pence: × 100. Never write £ and p together. |
| Comparing money | Change to the same unit (pence) first. £3.40 = 340p, which is more than 304p. |
| Adding and subtracting money | Line up the decimal points. Pence first, then pounds. Carry 100p as £1 or exchange £1 for 100p. Estimate to check. |
| Change | Change = money paid − total cost. Or count up from the cost to the next pound, then to the money paid. |
| Multiplying and sharing money | Multiply the pounds and the pence separately and change pence over 99 to pounds. To share, change to pence and divide. |
| Measures with decimals | Line up the decimal points and write 2.5 as 2.50 to add or subtract: 2.50 + 1.75 = 4.25. Cm ÷ 100 = m, mm ÷ 10 = cm. |
Can you…?
- I can write tenths and hundredths as fractions and as decimals.
- I know the value of each digit in a number with up to two decimal places.
- I can show decimals on a place-value chart, a hundred square and a number line.
- I can count up and down in tenths and hundredths, including across a whole number.
- I know 1/2 = 0.5, 1/4 = 0.25 and 3/4 = 0.75.
- I can divide a one- or two-digit number by 10 and by 100 and write the answer as a decimal.
- I can compare and order decimals with up to two decimal places.
- I can round a decimal with one decimal place to the nearest whole number.
- I can write amounts of money correctly, change between pounds and pence, and compare money.
- I can add and subtract money using columns, and work out change.
- I can multiply and share money and solve multi-step money problems.
- I can add and subtract measures written as decimals.
Key terms
- Decimal
- A number with a decimal point, like 3.45. The digits after the point are parts of a whole.
- Decimal point
- The dot that separates the whole numbers from the parts of a whole.
- Tenth
- One of 10 equal parts of a whole: 1/10 = 0.1.
- Hundredth
- One of 100 equal parts of a whole: 1/100 = 0.01.
- Decimal place
- A column after the decimal point. 0.47 has two decimal places.
- Place value
- The value of a digit because of the column it is in.
- Hundred square
- A square cut into 100 small squares. Each small square is one hundredth.
- Equivalent
- Having the same value, like 1/2 and 0.5.
- Compare
- To say which of two numbers is bigger or smaller.
- Order
- To put numbers in a list, smallest first or biggest first.
- Round
- To change a number to a nearby number that is easier to use, like 3.6 to 4.
- Pence (p)
- Small units of money. 100p = £1.
- Pound (£)
- A unit of money. £1 = 100p.
- Change
- The money you get back when you pay with more than the cost.
- Total
- All the amounts added together.
- Estimate
- To find an approximate answer by rounding the numbers first.
- Convert
- To change an amount from one unit to another, like cm to m.
Exercise 6Z Check-up (non-calculator)
Non-calculatorKey words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Count the tenths that are shaded. Tenths are the first column after the decimal point.
- Count the equal parts in the whole. The whole is cut into 10 equal parts. Each part is one tenth.There are 10 parts, so the bottom number is 10.
- Count the shaded parts. This gives the top number.6 parts are shaded, so the fraction is
.6 10 - Write it as a decimal. Tenths go in the first column after the decimal point.
ones tenths 0.6 0 . 6
0 ones and 6 tenths = 0.6
Check. Go back to a fraction: 0.6 has 6 in the tenths column, so it is
Watch out. Write the 0 ones before the decimal point: 0.7, not .7.
Key words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. Look at the bottom number: 10 means tenths and 100 means hundredths. Put the digits in a place-value table and write the decimal point after the ones.
- Look at the bottom number. 100 means hundredths. Tenths go in the first column after the point and hundredths in the second column.
is 7 hundredths.7 100 - Notice there are no tenths. 7 hundredths is less than 1 tenth (1 tenth = 10 hundredths). The tenths column must hold a 0.0 tenths and 7 hundredths
- Write the digits in the place-value table. Put each digit in its column. The decimal point goes after the ones.
ones tenths hundredths 0.07 0 . 0 7 - Write the decimal.
= 0.077 100
Check. Go back to a fraction: 0.07 =
Watch out. 7 hundredths is 0.07, not 0.7. The 0 in the tenths column keeps the 7 in the hundredths column.
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write the decimal as hundredths. Then divide the top and the bottom by the same number to make it simpler.
- Write the part after the point as hundredths. Two digits after the point mean the bottom number is 100. If there is only one digit, write a 0 after it first: 0.5 = 0.50.75 hundredths =
75 100 - Find a number that divides into the top and the bottom. The biggest one makes the fraction as simple as possible.75 and 100 both divide by 25.
- Divide the top and the bottom by it. Dividing both by the same number does not change the value.75 ÷ 25 = 3 and 100 ÷ 25 = 4
=75 100 3 4 - Write the fraction. 0.75 =
3 4
Check. Go back to a decimal:
Watch out. Do not forget to simplify: 0.75 is 3/4, and 75/100 is the same amount written in a longer way.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Find which column the digit is in. The value is the digit times the value of that column.
- Write the number in a place-value table. This shows which column each digit is in.
ones tenths hundredths 5.38 5 . 3 8 - Find the column the digit is in. The columns, from the left, are tens, ones, then after the decimal point tenths and hundredths.The digit 3 is in the tenths column.
- Work out its value. One tenth is worth 0.1. The digit tells us how many of them there are.3 × 0.1 = 0.3
- Write the answer. 3 tenths (0.3)
Check. Check by adding up all the parts: they should make 5.38. ✓
Watch out. The 0.5 in a number like 3.52 is worth 5 tenths (0.5), not 5 ones.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 100 moves each digit 2 places to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 100 makes every digit 100 times smaller.
- Move every digit 2 columns to the right. Each digit slides two columns to the right, because dividing by 100 is dividing by 10 twice.
- Fill the empty ones column with a 0. A number like 0.53 starts with 0 ones. The 0 holds the place.0 ones
- Write the answer. Put the decimal point after the ones.56 ÷ 100 = 0.56
Check. Go the other way: 0.56 × 100 = 56. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. To order numbers is to put them in a list. Ascending means smallest first. Descending means biggest first.
Method. Write the numbers in a place-value table and compare the digits column by column, starting from the left. Then list them smallest first.
- Write the numbers in a place-value table. Line up the decimal points.
ones tenths hundredths 0.61 0 . 6 1 0.16 0 . 1 6 0.66 0 . 6 6 - Compare the columns from the left. Where the digits are the same, look at the next column to the right.Ones: 0.61 has 0, 0.16 has 0, 0.66 has 0. All the same, so look at the next column.
Tenths: 0.61 has 6, 0.16 has 1, 0.66 has 6. Smallest to biggest: 1, 6.
Hundredths: 0.61 has 1, 0.66 has 6. Smallest to biggest: 1, 6. - Write them smallest first. Write the ORIGINAL numbers and check that you have used every one.0.16, 0.61, 0.66
Check. Count them: 3 numbers in the question and 3 in the answer. ✓
Watch out. Do not forget a number. Tick each one off as you write it.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 6.7 is between. Rounding to the nearest whole number means choosing the closest whole number.6 < 6.7 < 7
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 7.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)7 is 5 or more, so round up.
- Write the answer. 6.7 ≈ 7 (to the nearest whole number)
Check. Distances: 6.7 − 6 = 0.7 and 7 − 6.7 = 0.3. 7 is the nearer whole number. ✓
Watch out. Only the tenths digit decides. A number like 3.49 rounds down, even though 9 is big: look at the first digit after the point only.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Divide the pence by 100 to find the pounds. The pence left over go after the decimal point, with two digits.
- Remember: 100 pence make 1 pound. So we divide the pence by 100 to find the pounds.605 ÷ 100 = 6 remainder 5
- Write the pounds and the pence. 6 pounds and 5p.6 pounds and 5p
- Put them together with a decimal point. The pence always get TWO digits: write a 0 in front if there is only one.£6.05 (the 0 holds the tens-of-pence place)
Check. Go back: £6.05 = 6 × 100 + 5 = 605p. ✓
Watch out. Do not write £6.5: money always has two digits after the point.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Add up the cost of everything. Then take the total cost away from the money that was paid. What is left is the change.
- Draw a bar model. The whole bar is the money we pay with. It is split into the cost of what we buy and the change.
- Step 1: find the change. Take the cost away from the money paid.£10.00 − £3.85 = £6.15
£10 £1 10p 1p £ 0 19 0. 9 010 0− £ 3 . 8 5 £ 6 . 1 5 - Write the answer. The change is £6.15
Check. Add the change to the cost: £3.85 + £6.15 = £10.00, the money paid. ✓
Watch out. Take the cost away from the money paid, not the other way round.
Key words. Lengths, masses and capacities can be written as decimals: 2.5 m is two and a half metres, 1.75 kg is 1 and 3/4 kilograms. Line up the decimal points to add or subtract.
Method. Line up the decimal points with the bigger number on top. Subtract column by column from the right. Exchange when a top digit is too small. Write the unit.
- Give both numbers the same number of decimal places. Adding a 0 on the end of a decimal does not change its value. It helps the digits line up.3.5 = 3.50
- Line up the amounts in columns. The bigger number goes on top. Put the decimal points in a straight line.
O t h 3 . 5 0 − 1 . 7 5 . - Exchange, then subtract the hundredths. The top digit is smaller than the bottom digit, so we swap 1 from the next column.0 is not enough to take away 5. We need to exchange.
Exchange 1 from the tenths column: 5 becomes 4, and the hundredths column goes from 0 to 10.
10 − 5 = 5 - Exchange, then subtract the tenths. The top digit is smaller than the bottom digit, so we swap 1 from the next column.4 is not enough to take away 7. We need to exchange.
(There were 5 in this column to start with, but we gave one away in an earlier exchange.)
Exchange 1 from the ones column: 3 becomes 2, and the tenths column goes from 4 to 14. (This crosses the decimal point.)
14 − 7 = 7 - Subtract the ones. Now the next column to the left.(This digit is 2 now, not 3, because we exchanged from this column.)
2 − 1 = 1 - Read the answer. Put the decimal point in the answer, directly under the other decimal points.
O t h 2 3. 14 510 0− 1 . 7 5 1 . 7 5
3.50 m − 1.75 m = 1.75 m
Check. Add back: 1.75 m + 1.75 m = 3.50 m. ✓
Watch out. Line up the decimal points, not the right-hand digits: 2.5 has fewer digits than 1.75, so write 2.50.
Total 17 marks. Allow about 17 minutes.
Exercise 6X SATs-style questions
Non-calculatorKey words. A decimal is a number with a decimal point. The digits after the point are parts of one whole: the first column is tenths and the second column is hundredths.
Method. A hundred square has 100 small squares. Each is one hundredth. Count the shaded squares, then write the decimal.
- Count the small squares in the whole. There are 10 rows of 10 small squares. Each small square is one hundredth.10 × 10 = 100 squares
- Count the shaded squares. Count the full rows first (10 squares each), then the extra squares.3 full rows = 30 squares
30 + 6 = 36 squares - Write the fraction. The top number is the shaded squares.
36 100 - Write it as a decimal. Tenths are the first column after the point and hundredths are the second column.
ones tenths hundredths 0.36 0 . 3 6
36 hundredths = 0 ones, 3 tenths and 6 hundredths, so 0.36
Check. Go back: 0.36 is
Watch out. Each row of 10 squares is one tenth (0.1). Count in tens to be quick.
Key words. To divide by 10 is to make a number 10 times smaller. The digits move one column to the right. Dividing by 100 moves them two columns.
Method. Dividing by 10 moves each digit 1 place to the right in the place-value chart.
- Write the number in a place-value chart. Dividing by 10 makes every digit 10 times smaller.
- Move every digit 1 column to the right. Each digit slides one column to the right, to a column that is worth 10 times less.
- Write the answer. Put the decimal point after the ones.84 ÷ 10 = 8.4
Check. Go the other way: 8.4 × 10 = 84. ✓
Watch out. The digits move to the right (they get smaller). Do not just add a 0 on the end.
Key words. Place value means that a digit is worth different amounts in different columns. After the decimal point the columns are tenths (0.1) and hundredths (0.01).
Method. Find which column the digit is in. The value is the digit times the value of that column.
- Write the number in a place-value table. This shows which column each digit is in.
ones tenths hundredths 6.72 6 . 7 2 - Find the column the digit is in. The columns, from the left, are tens, ones, then after the decimal point tenths and hundredths.The digit 7 is in the tenths column.
- Work out its value. One tenth is worth 0.1. The digit tells us how many of them there are.7 × 0.1 = 0.7
- Write the answer. 7 tenths (0.7)
Check. Check by adding up all the parts: they should make 6.72. ✓
Watch out. The 0.5 in a number like 3.52 is worth 5 tenths (0.5), not 5 ones.
Key words. To round a number to the nearest whole number is to change it to the whole number that is closest to it. ≈ means “is about equal to”.
Method. Look at the tenths digit (just after the decimal point). If it is 5 or more, round up. If it is 4 or less, round down.
- Find the two whole numbers that 12.6 is between. Rounding to the nearest whole number means choosing the closest whole number.12 < 12.6 < 13
- Look at the tenths digit. It is the digit just after the decimal point. It tells us if we are past halfway.The tenths digit is 6.
- Decide: round up or round down? 5 or more: round up. 4 or less: round down. (Halfway, like 0.5, rounds up.)6 is 5 or more, so round up.
- Write the answer. 12.6 ≈ 13 (to the nearest whole number)
Check. Distances: 12.6 − 12 = 0.6 and 13 − 12.6 = 0.4. 13 is the nearer whole number. ✓
Watch out. Only the tenths digit decides. A number like 3.49 rounds down, even though 9 is big: look at the first digit after the point only.
A 0.5 B 0.05 C
Key words. A hundred square has 100 small squares. Each small square is 1 hundredth. A half is 1 of 2 equal parts and a quarter is 1 of 4 equal parts.
Method. Write each one as a decimal or a fraction and compare it with one half, which is 0.5.
- Write 1/2 as a decimal. A half is 5 tenths, or 50 hundredths.
= 0.51 2 - Check each option. A: 0.5 is a half ✓
B: 0.05 is 5 hundredths, not a half
C: is 5 tenths, which is a half ✓5 10
D: 0.25 is a quarter, not a half - Choose the two. A and C
Check. A half of 100 squares is 50 squares, which is 0.5 or 5 tenths. ✓
Watch out. 0.5 and 0.05 are different numbers.
Show how you know.[2 marks]
Key words. To order numbers is to put them in a list. Ascending means smallest first. Descending means biggest first.
Method. Write the numbers in a place-value table and compare the digits column by column, starting from the left. Then list them smallest first.
- Write the numbers in a place-value table. Line up the decimal points.
ones tenths hundredths 4.35 4 . 3 5 4.53 4 . 5 3 4.05 4 . 0 5 - Compare the columns from the left. Where the digits are the same, look at the next column to the right.Ones: 4.35 has 4, 4.53 has 4, 4.05 has 4. All the same, so look at the next column.
Tenths: 4.35 has 3, 4.53 has 5, 4.05 has 0. Smallest to biggest: 0, 3, 5. - Write them smallest first. Write the ORIGINAL numbers and check that you have used every one.4.05, 4.35, 4.53
Check. Count them: 3 numbers in the question and 3 in the answer. ✓
Watch out. Do not forget a number. Tick each one off as you write it.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Multiply the pounds by 100 and add the pence.
- Remember: 1 pound is 100 pence. So we multiply the pounds by 100.6 × 100 = 600p
- Add the pence. The two digits after the decimal point are the pence.600p + 5p = 605p
- Write the answer with the unit p. Pence are written with a small p after the number.£6.05 = 605p
Check. Go back: 605p ÷ 100 = £6.05. ✓
Watch out. £6.05 is 605p, not 65p: if the pence are less than 10, put a 0 in: £6.05 = 605p.
Key words. To compare numbers is to say which is bigger. < means “is less than” and > means “is greater than”.
Method. Compare the numbers column by column from the left, not as whole numbers. Give them the same number of decimal places first.
- Look at what Aisha did. Aisha compared 65 and 7 as if they were whole numbers.65 > 7, so Aisha thinks 0.65 > 0.7
- Give both numbers the same number of decimal places. Adding a 0 on the end does not change the value.0.7 = 0.70
- Compare them in a place-value table. Look at the tenths first.
ones tenths hundredths 0.65 0 . 6 5 0.70 0 . 7 0 - Decide who is right. 0.65 < 0.7. Aisha is wrong.
Check. On a number line, 0.7 = 0.70 is to the right of 0.65. ✓
Watch out. A decimal with more digits is not always bigger. Compare tenths first, then hundredths.
Key words. Pence (p) are small amounts of money: 100p = £1. Change is the money you get back when you pay with more than the cost. The total is all the amounts added together.
Method. Find the cost of each group of items. Add them to find the total. Then take the total away from the money paid to find the change.
- Find the cost of 3 apples. 3 lots of £0.45.3 × £0.45 = £1.35 (45p × 3 = 135p)
- Add the costs to find the total. Use a column method, with the decimal points lined up.£1.35 + £1.20 = £2.55
£1 10p 1p £ 1 . 3 5 + £ 1 . 2 0 £ 2 . 5 5 - Take the total cost away from the money paid. What is left is the change.£5.00 − £2.55 = £2.45
£1 10p 1p £ 4 5. 9 010 0− £ 2 . 5 5 £ 2 . 4 5 - Write the answer. The change is £2.45
Check. Add the change to the total: £2.55 + £2.45 = £5.00. ✓
Watch out. Multiply first, then add, then subtract from the money paid.
Key words. Lengths, masses and capacities can be written as decimals: 2.5 m is two and a half metres, 1.75 kg is 1 and 3/4 kilograms. Line up the decimal points to add or subtract.
Method. First find the total length cut off. Then take it away from the whole ribbon.
- Step 1: add the two pieces. This gives the total length cut off.1.25 m + 0.75 m
1.25 + 0.75 = 2.00 mO t h 1 . 2 5 + 0 . 7 5 2 . 0 0 1 1 - Step 2: take the total away from the whole ribbon. Write 3.5 as 3.50 so the decimal points and digits line up.3.50 m − 2.00 m
3.50 − 2.00 = 1.50 mO t h 3 . 5 0 − 2 . 0 0 1 . 5 0 - Write the answer. 1.50 m is the same as 1.5 m.1.5 m
Check. Add back: 1.5 + 1.25 + 0.75 = 3.5. ✓
Watch out. Take away the TOTAL of the two pieces, not just one piece.