Year 4: Halves, quarters and three quarters
Part of the Year 4 tenths, hundredths and money chapter. Chapter overview · whole chapter on one page · Download worksheet (PDF) · Answers (PDF)
Halves, quarters and three quarters
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.