Level 5 check
By the end of this chapter you will be able to
- Answer a mix of Level 5 questions
- Show secure place value to a million and decimals to tenths
- Show secure column methods for adding, subtracting, multiplying and dividing
- Show secure fractions, decimals and measures
- Show secure perimeter, time and money problems
You should already know
- Chapters 1 to 9 of Level 5
Where this leads
- Level 6: long division with two-digit divisors, and remainders as fractions or decimals
Step-by-step practice: maths (Level 5). Small steps, repeated until fluent. Content: Read, write, order and compare numbers to 1,000,000, and know place value (chapter 1), Add and subtract whole numbers to a million in columns (chapter 2), Recall the times tables to 12 times 12, and multiply by 11 and 12 (chapter 3), Multiply a two-digit number by a one-digit number with the written method (chapter 4), Divide a two-digit number by a one-digit number with remainders (chapter 5), Add and subtract fractions with the same denominator (chapter 6), Decimals to hundredths, and rounding decimals (chapter 7), Convert metric measures and solve measure problems (chapter 8), Perimeter, time and money problems (chapter 9).
Exercise P Do you remember?
Non-calculatorMethod. The 6 is in the hundreds column, so its value is 6 hundreds.
- Find the hundreds column. Count from the right: ones, tens, hundreds.Hundreds column
- Multiply the digit by 100. Each hundreds place is worth 100.6 × 100 = 600
- Write the value. This is the value of the 6.600
Check. Check: 600 is 6 groups of 100.
Watch out. The value is 600, not 6.
Method. Add the columns from the right. Carry any ten into the next column on the left.
- Add the ones column. Write 4 and carry 1 to the tens column.5 + 9 = 14
- Add the tens column. Write 9 in the tens column.7 + 1 + 1 carried = 9
- Add the hundreds column. Write 1 and carry 1 to the thousands column.3 + 8 = 11
- Add the thousands column. Write 7 in the thousands column.4 + 2 + 1 carried = 7
- Write the answer. Put the digits together, with commas between groups of three.7,194
Check. Check: 7,194 - 2,819 = 4,375.
Watch out. Carry the 1 into the next column. Do not forget it, and do not write it as a digit in its own column.
Method. Count in 4s to find 6 groups of 4. The order of the numbers does not matter.
- Count in 4s, 6 times. Each count adds one more group of 4.4, 8, 12, 16, 20, 24
- The last number we said is the answer. We counted 6 groups of 4.4 × 6 = 24
- Write the answer. The order of the two numbers does not change the answer.24
Check. Check: 6 × 4 is also 24.
Watch out. Learn the 4 times table in order, then say it in any order.
Method. Multiply the ones first, carry the tens.
- Multiply the ones. Write the ones digit and carry the tens.8 × 4 = 32, write 2 and carry 3
- Multiply the tens and add the carried 3. Add the carried number before you write the tens digit.3 × 4 = 12, plus 3 = 15
- Write the answer. Put the digits together.152
Check. Check: 152 ÷ 4 = 38.
Watch out. Add the carried number to the tens product.
Method. Compare the top numbers.
- Look at the bottom numbers. Both are eighths.Both are eighths
- Compare the top numbers. More eighths is greater.5 and 3
- Choose the greater. 5 eighths is more than 3 eighths.5/8
Check. Check: 5 parts is more than 3 parts of the same size.
Watch out. Compare the top numbers when the bottom numbers are the same.
Numbers to a million, and decimals to tenths
This section mixes the skills from chapters 1 and 7. Read each question, then write the answer.
Name the column first when you find the value of a digit. Round by looking at the digit on the right.
Key ideas
- Name the column, then multiply the digit by its value.
- Adding 10,000 changes the ten thousands digit.
- Round by looking one column to the right.
Method. Read the column, then multiply the digit by the value of that column.
- Find the ten thousands column. Count the columns from the right: ones, tens, hundreds and so on.The digit is 7
- Multiply the digit by the value of its column. Each place in the ten thousands column is worth 10,000.7 × 10,000 = 70,000
- Write the value. This is the value of the digit in this number, not just the digit.70,000
Check. Check: 70,000 is 7 groups of 10,000.
Watch out. Say the value, such as 70,000, not only the digit 7.
Method. Only the ten thousands digit changes when we add or take away 10,000.
- Look at the ten thousands digit. Adding or taking away 10,000 changes this digit by one.The ten thousands digit is 9
- Change that digit by one. Carry or borrow if the digit goes past 9 or below 0.9 + 1 = 10, so write 0 and carry 1 into the hundred thousands
- Write the answer. All the other digits stay the same.305,000
Check. Check: 305,000 take away 10,000 gives back 295,000.
Watch out. Do not change the thousands digit. 10,000 is not 1,000.
Method. Look at the digit to the right of the thousands column, then decide.
- Look at the hundreds digit. This digit decides whether to round up or down.The hundreds digit is 8
- Decide: round up or down. 5 or more: round up. 4 or less: round down.8 is 5 or more, so round up
- Write the rounded number. Replace the digits after the thousands column with zeros.473,000
Check. Check: 473,000 is a multiple of 1,000 and is the closest one to 472,893.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Watch out
Watch out. The 7 in 472,893 is worth 70,000, not 7. Say the value with its column.
Exam tip
Grown-up tip. Ask the child to explain how they found the answer, not only to say it.
Exercise 10A Mixed practice: numbers and decimals
Non-calculatorMethod. Read the column, then multiply the digit by the value of that column.
- Find the hundred thousands column. Count the columns from the right: ones, tens, hundreds and so on.The digit is 1
- Multiply the digit by the value of its column. Each place in the hundred thousands column is worth 100,000.1 × 100,000 = 100,000
- Write the value. This is the value of the digit in this number, not just the digit.100,000
Check. Check: 100,000 is 1 groups of 100,000.
Watch out. Say the value, such as 70,000, not only the digit 7.
Method. Compare the whole numbers, then the tenths.
- Compare the whole numbers first. The bigger whole number is the bigger decimal.9 and 3
- If the whole numbers are the same, compare the tenths. The tenths digit decides when the whole numbers match.2 and 9 tenths
- Choose the greater decimal. This is the decimal with more of the bigger part.9.2
Check. Check: 9.2 is 92 tenths, and 3.9 is 39 tenths.
Watch out. 3.7 is greater than 3.4, not smaller. Compare the tenths: 7 tenths is more than 4 tenths.
Method. Only the ten thousands digit changes when we add or take away 10,000.
- Look at the ten thousands digit. Adding or taking away 10,000 changes this digit by one.The ten thousands digit is 6
- Change that digit by one. Carry or borrow if the digit goes past 9 or below 0.6 - 1 = 5
- Write the answer. All the other digits stay the same.251,850
Check. Check: 251,850 add 10,000 gives back 261,850.
Watch out. Do not change the thousands digit. 10,000 is not 1,000.
Method. Look at the digit to the right of the thousands column, then decide.
- Look at the hundreds digit. This digit decides whether to round up or down.The hundreds digit is 6
- Decide: round up or down. 5 or more: round up. 4 or less: round down.6 is 5 or more, so round up
- Write the rounded number. Replace the digits after the thousands column with zeros.822,000
Check. Check: 822,000 is a multiple of 1,000 and is the closest one to 821,656.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the hundred thousands column, then decide.
- Look at the ten thousands digit. This digit decides whether to round up or down.The ten thousands digit is 2
- Decide: round up or down. 5 or more: round up. 4 or less: round down.2 is 4 or less, so round down
- Write the rounded number. Replace the digits after the hundred thousands column with zeros.100,000
Check. Check: 100,000 is a multiple of 100,000 and is the closest one to 128,473.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Compare the digits from the left. The first column where they differ decides.
- Compare the two numbers from the left. Look at the digits in the same column, starting with the largest.5 and 5 in the first column
- Find the first column where they differ. That column decides which number is greater.In the ten thousands column: 6 and 3
- Choose the greater number. The number with the greater digit in that column is greater.561,644
Check. Check: the other number is 535,634, which is smaller.
Watch out. Do not compare the last digits first. Start from the left.
Method. Compare the whole numbers first, then the tenths.
- Compare the whole numbers. Put the numbers with the smallest whole number first.4, 7, 8, 1
- Compare the tenths when the whole numbers match. Use the tenths digit to break a tie.4.9, 7.1, 8.9, 1.1
- Write the list smallest first. Read the order from the smallest to the largest.1.1, 4.9, 7.1, 8.9
Check. Check: the first number is the smallest and the last is the greatest.
Watch out. Do not order by the number of digits after the point. 4.2 is greater than 3.9.
Method. The first digit after the point is the number of tenths.
- Find the tenths digit. It is the first digit after the decimal point.The digit is 5
- Write its value. 5 tenths is 5/10.5/10 = 0.5
- Write the answer. The value of the digit is a decimal less than one.0.5
Check. Check: 0.5 + 4 = 4.5.
Watch out. Do not write the digit as a whole number. 4 in 3.4 is 0.4, not 4.
Method. Compare the whole numbers first, then the tenths.
- Compare the whole numbers. Put the numbers with the smallest whole number first.9, 6, 4, 6
- Compare the tenths when the whole numbers match. Use the tenths digit to break a tie.9.6, 6.1, 4.5, 6.5
- Write the list smallest first. Read the order from the smallest to the largest.4.5, 6.1, 6.5, 9.6
Check. Check: the first number is the smallest and the last is the greatest.
Watch out. Do not order by the number of digits after the point. 4.2 is greater than 3.9.
Method. Only the ten thousands digit changes when we add or take away 10,000.
- Look at the ten thousands digit. Adding or taking away 10,000 changes this digit by one.The ten thousands digit is 8
- Change that digit by one. Carry or borrow if the digit goes past 9 or below 0.8 + 1 = 9
- Write the answer. All the other digits stay the same.595,397
Check. Check: 595,397 take away 10,000 gives back 585,397.
Watch out. Do not change the thousands digit. 10,000 is not 1,000.
Method. Only the ten thousands digit changes when we add or take away 10,000.
- Look at the ten thousands digit. Adding or taking away 10,000 changes this digit by one.The ten thousands digit is 6
- Change that digit by one. Carry or borrow if the digit goes past 9 or below 0.6 + 1 = 7
- Write the answer. All the other digits stay the same.572,618
Check. Check: 572,618 take away 10,000 gives back 562,618.
Watch out. Do not change the thousands digit. 10,000 is not 1,000.
Method. Read the column, then multiply the digit by the value of that column.
- Find the hundred thousands column. Count the columns from the right: ones, tens, hundreds and so on.The digit is 5
- Multiply the digit by the value of its column. Each place in the hundred thousands column is worth 100,000.5 × 100,000 = 500,000
- Write the value. This is the value of the digit in this number, not just the digit.500,000
Check. Check: 500,000 is 5 groups of 100,000.
Watch out. Say the value, such as 70,000, not only the digit 7.
Method. Partition the number into the value of each digit.
- Find the value of each digit. Multiply each digit by the value of its column; leave out zeros.300,000, 70,000, 500, 40, 3
- Write the parts as an addition. Add the parts together to make the number.300,000 + 70,000 + 500 + 40 + 3
- Check by adding. Adding the parts again must give the number we started with.300,000 + 70,000 + 500 + 40 + 3
Check. Check: the parts add to 370,543.
Watch out. Leave out any digit that is zero. Zero adds nothing.
Method. Look at the digit to the right of the ten thousands column, then decide.
- Look at the thousands digit. This digit decides whether to round up or down.The thousands digit is 2
- Decide: round up or down. 5 or more: round up. 4 or less: round down.2 is 4 or less, so round down
- Write the rounded number. Replace the digits after the ten thousands column with zeros.900,000
Check. Check: 900,000 is a multiple of 10,000 and is the closest one to 902,770.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Look at the digit to the right of the ten thousands column, then decide.
- Look at the thousands digit. This digit decides whether to round up or down.The thousands digit is 8
- Decide: round up or down. 5 or more: round up. 4 or less: round down.8 is 5 or more, so round up
- Write the rounded number. Replace the digits after the ten thousands column with zeros.160,000
Check. Check: 160,000 is a multiple of 10,000 and is the closest one to 158,297.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. The first digit after the point is the number of tenths.
- Find the tenths digit. It is the first digit after the decimal point.The digit is 8
- Write its value. 8 tenths is 8/10.8/10 = 0.8
- Write the answer. The value of the digit is a decimal less than one.0.8
Check. Check: 0.8 + 9 = 9.8.
Watch out. Do not write the digit as a whole number. 4 in 3.4 is 0.4, not 4.
Adding, subtracting, multiplying and dividing
Line up the digits in columns. Carry when you add; exchange when you subtract; carry the tens when you multiply.
In short division, share the tens first, then the ones, and write any remainder after the answer.
Key ideas
- Work from the right in columns.
- Carry or exchange as you go.
- Check each answer with the inverse.
Method. Add the columns from the right. Carry any ten into the next column on the left.
- Add the ones column. Write 7 in the ones column.4 + 3 = 7
- Add the tens column. Write 5 and carry 1 to the hundreds column.8 + 7 = 15
- Add the hundreds column. Write 3 and carry 1 to the thousands column.3 + 9 + 1 carried = 13
- Add the thousands column. Write 4 and carry 1 to the ten thousands column.5 + 8 + 1 carried = 14
- Add the ten thousands column. Write 1 and carry 1 to the hundred thousands column.6 + 4 + 1 carried = 11
- Add the hundred thousands column. Write 3 in the hundred thousands column.2 + 0 + 1 carried = 3
- Write the answer. Put the digits together, with commas between groups of three.314,357
Check. Check: 314,357 - 48,973 = 265,384.
Watch out. Carry the 1 into the next column. Do not forget it, and do not write it as a digit in its own column.
Method. Subtract each column from the right. Exchange 1 from the column on the left when the top digit is too small.
- Subtract the ones column. 0 is less than 8. The tens and hundreds and thousands and ten thousands are 0, so exchange across them: take 1 hundred thousands and make each zero a 9, which gives 10 ones.10 - 8 = 2
- Subtract the tens column. 9 is at least 6, so subtract directly.9 - 6 = 3
- Subtract the hundreds column. 9 is at least 4, so subtract directly.9 - 4 = 5
- Subtract the thousands column. 9 is at least 3, so subtract directly.9 - 3 = 6
- Subtract the ten thousands column. 9 is at least 7, so subtract directly.9 - 7 = 2
- Subtract the hundred thousands column. 4 is at least 2, so subtract directly.4 - 2 = 2
- Write the answer. Read the digits from the left, and put commas in.226,532
Check. Check: 273,468 + 226,532 = 500,000.
Watch out. When you exchange across zeros, change each zero to 9 as you pass it. Do not leave a zero in the middle.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 6. Write 8 in the ones column and carry 4 to the tens column.8 × 6 = 48
- Multiply the tens digit by 6. Write 2 in the tens column and carry 2 to the hundreds column.3 × 6 = 18, plus 4 carried = 22
- Write the carried number in front. The carried number is the next digit on the left.2 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.228
Check. Check: 228 ÷ 6 = 38.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Watch out
Watch out. Do not forget a carried 1 or an exchange. Check the answer with the inverse operation.
Exam tip
Grown-up tip. Ask: “Did you carry, exchange or add the carried number? Does your check work?”
Exercise 10B Mixed practice: adding, subtracting, multiplying and dividing
Non-calculatorMethod. Split 12 into 10 and 2, then add the two results.
- Split 12 into 10 and 2. Multiply each part by the number.12 × 11 = 10 × 11 + 2 × 11
- Work out each part. Both parts are facts we know.10 × 11 = 110, and 2 × 11 = 22
- Add the two parts. The total is the answer.110 + 22 = 132
- Write the answer. This is the answer to 12 times the number.132
Check. Check: 132 ÷ 12 = 11.
Watch out. Do not add 12 to the number only once. Work out both parts.
Method. Multiply the number in each group by the number of groups, or the amount by the number of times.
- Find the scaling number. Lee has the number of times as many as Sam.4 times 53
- Multiply. Scaling is multiplying by the number of times.53 × 4 = 212
- Write the answer. This is the number of stamps Lee has.212 stamps
Check. Check: 212 is more than the first number, because we multiplied by 4.
Watch out. Check the units: the answer should be in the same unit as the question (pencils, pence, stamps).
Method. Check by using the inverse: subtract for a sum, or add back for a difference.
- Take one number away from the answer. If the sum is correct, taking one number away gives the other.918,021 - 746,477 = 171,544
- Compare with the other number. Is 171,544 the same as 171,544?Same
- Write Yes or No. Yes if the check works; No if it does not.Yes
Check. The correct answer is 918,021.
Watch out. A check that does not work means the answer is wrong. Find the mistake in the columns.
Method. Subtract each column from the right. Exchange 1 from the column on the left when the top digit is too small.
- Subtract the ones column. 3 is less than 7, so exchange 1 tens for 10 ones.13 - 7 = 6
- Subtract the tens column. 6 is less than 7. The hundreds is 0, so exchange across them: take 1 thousands and make each zero a 9, which gives 10 tens.16 - 7 = 9
- Subtract the hundreds column. 9 is at least 6, so subtract directly.9 - 6 = 3
- Subtract the thousands column. 4 is at least 3, so subtract directly.4 - 3 = 1
- Subtract the ten thousands column. 8 is at least 1, so subtract directly.8 - 1 = 7
- Subtract the hundred thousands column. 5 is at least 4, so subtract directly.5 - 4 = 1
- Write the answer. Read the digits from the left, and put commas in.171,396
Check. Check: 413,677 + 171,396 = 585,073.
Watch out. When you exchange across zeros, change each zero to 9 as you pass it. Do not leave a zero in the middle.
Method. Round up when the remainder still needs one more group.
- Divide to find the full buses and what is left. 27 children in buses of 5.27 ÷ 5 = 5 remainder 2
- Decide what the remainder means. The children left over still need a bus, so round up.2 children left over need 1 more bus
- Write the answer. Round up when the leftover people still need a place.6 buses
Check. Check: 6 buses hold 30 children, which is at least 27.
Watch out. Round up when the leftover still needs a place. Do not give the answer with a remainder.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 9. Write 4 in the ones column and carry 5 to the tens column.6 × 9 = 54
- Multiply the tens digit by 9. Write 6 in the tens column and carry 8 to the hundreds column.9 × 9 = 81, plus 5 carried = 86
- Write the carried number in front. The carried number is the next digit on the left.8 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.864
Check. Check: 864 ÷ 9 = 96.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Check by using the inverse: subtract for a sum, or add back for a difference.
- Take one number away from the answer. If the sum is correct, taking one number away gives the other.882,437 - 597,023 = 285,414
- Compare with the other number. Is 285,414 the same as 275,414?Not the same
- Write Yes or No. Yes if the check works; No if it does not.No
Check. The correct answer is 872,437.
Watch out. A check that does not work means the answer is wrong. Find the mistake in the columns.
Method. Find the multiple of the divisor that is just below the number. It tells you the whole number of groups.
- Count in 7s. Keep counting until you go past 51.7, 14, ... up to 51
- Find the largest multiple. It is the last multiple that is not more than the number.49 is not more than 51
- Write the multiple. This is the number that helps you find the division.49
Check. Check: 7 × 7 = 49, and 49 is not more than 51.
Watch out. Do not pick the multiple just above the number; it is more than the number.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 3. Write 5 in the ones column and carry 1 to the tens column.5 × 3 = 15
- Multiply the tens digit by 3. Write 4 in the tens column.1 × 3 = 3, plus 1 carried = 4
- Multiply the hundreds digit by 3. Write 6 in the hundreds column.2 × 3 = 6
- Write the answer. Read the digits from the bottom of each column, from the left.645
Check. Check: 645 ÷ 3 = 215.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 7. Write 0 in the ones column.0 × 7 = 0
- Multiply the tens digit by 7. Write 7 in the tens column.1 × 7 = 7
- Write the answer. Read the digits from the bottom of each column, from the left.70
Check. Check: 70 ÷ 7 = 10.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Use the short method. Share the tens first, then the ones with what is left.
- The tens are fewer than the number of groups. 3 tens cannot make a group of 9 on their own, so use all of 30.30 is the number to share
- Share 30 into groups of 9. How many groups of 9 are in 30?30 ÷ 9 = 3 r 3
- Write the answer. The remainder is what is left over; write it after the answer.3 remainder 3
Check. Check: 3 × 9 + 3 = 30.
Watch out. The remainder must be smaller than the number you divide by.
Method. Use the inverse operation to find the missing number.
- Add the number taken away to the answer. Adding undoes subtracting.207,536 + 84,766
- Work out the sum. Use the column method.207,536 + 84,766 = 292,302
- Check by subtracting. The answer must go back to the missing number.292,302 - 84,766 = 207,536
- Write the missing number. This is the number in the box.292,302
Check. Check: put 292,302 into the sum and it works.
Watch out. To find a missing number in a sum, subtract. To find it in a difference, add.
Method. Divide, then check: answer × divisor + remainder = the number we started with.
- Find how many groups of 5 are in 15. Use the times table of the divisor.3 groups of 5 = 15
- Find what is left over. The remainder is the number left after the groups.15 - 15 = 0
- Check with multiplication and addition. Multiply the answer by the divisor, then add the remainder.3 × 5 + 0 = 15 + 0 = 15
- Write the answer. This is the answer with its remainder.3
Check. Check: 3 × 5 + 0 = 15.
Watch out. If the check does not give the number you started with, divide again.
Method. Count in 6s to find 11 groups of 6. The order of the numbers does not matter.
- Count in 6s, 11 times. Each count adds one more group of 6.6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66
- The last number we said is the answer. We counted 11 groups of 6.6 × 11 = 66
- Write the answer. The order of the two numbers does not change the answer.66
Check. Check: 11 × 6 is also 66.
Watch out. Learn the 6 times table in order, then say it in any order.
Method. Division with equal groups: the number of boxes is the total divided by the box size.
- Find the total and the size of each box. The total is how many; the box holds a certain number.108 cups in boxes of 12
- Think: how many groups of the box size make the total? This is a division, which we can check with the table.12 × ___ = 108
- Count the boxes. Count in the box size until you reach the total.12, 24, 36, 48, 60, 72, 84, 96, 108
- Write the answer. This is the number of boxes.9
Check. Check: 9 boxes of 12 hold 9 × 12 = 108 cups.
Watch out. Check the answer makes sense: each box holds the same number.
Method. Check with multiplication and addition: groups × divisor + remainder must equal the number, and the remainder must be smaller than the divisor.
- Multiply the whole number of groups by the divisor, then add the remainder. Check with multiplication and addition.5 × 6 + 0 = 30
- Compare with 30. The result must be 30, and the remainder must be smaller than 6.30 is the same as 30; 0 is smaller than 6
- Write Yes or No. Yes if the check works; No if it does not.Yes
Check. The correct answer is 5.
Watch out. A remainder that is as big as the divisor means the answer is wrong. Find the mistake if the check does not work.
Fractions, measures, perimeter, time and money
To add fractions with the same denominator, add the top numbers and keep the bottom number. Simplify when you can.
For time and money, count on in steps and keep the units and the decimal points in line.
Key ideas
- Add the top numbers; keep the bottom number.
- Change measures to the same unit first.
- Count on across the hour or midnight.
Method. More than one whole: add the top numbers, then write the whole ones out.
- Add the top numbers. Keep the bottom number the same.3 + 2 = 5
- Write the total. 5 parts of size 1/4.5/4
- Write as a mixed number. There are 1 whole one and 1/4 left over.5/4 = 1 1/4
- Write the answer. This is the answer in its simplest form.1 1/4
Check. Check: 1 1/4 is more than 1, as 5/4 is more than 4/4.
Watch out. A top number bigger than the bottom is more than one whole. Write it as a mixed number.
Method. Line up the decimal points and add in columns. Keep the pound sign and two places for pence.
- Line up the decimal points. Write the pounds and pence in columns.3.46 + 2.85
- Add the pence first. Carry any ten pence into the pounds.46 + 85 = 131 pence
- Add the pounds. Include any carried pounds.3 + 2 = 6 pounds
- Write the answer with the pound sign. Always write two places for the pence.£6.31
Check. Check: £6.31 - £2.85 = £3.46.
Watch out. Always write two digits for the pence: £5.00, not £5.
Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.
- Count the minutes to the next hour. Go from the start time to the next full hour.10:45 to 11:00 is 15 min
- Count the whole hours. Count each full hour after that.1 whole hours
- Count the minutes after the last whole hour. Count on to the arrival time.20 min
- Add the parts. Add all the parts for the total time.15 min + 1 h + 20 min = 1 h 35 min
- Write the answer. Give the journey time in hours and minutes.1 h 35 min
Check. Check: 1 h 35 min added to 10:45 gives 12:20.
Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.
Watch out
Watch out. 5/4 is 1 1/4, and 10:45 to 12:20 is 1 h 35 min. Check your answer makes sense.
Exam tip
Grown-up tip. Make a short list of the key rules: fractions, decimals, units and time. Practise one list each day.
Exercise 10C Mixed practice: fractions, measures, time and money
Non-calculatorMethod. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.
- Count the minutes to the next hour. Go from the start time to the next full hour.14:24 to 15:00 is 36 min
- Count the whole hours. Count each full hour after that.1 whole hours
- Count the minutes after the last whole hour. Count on to the arrival time.6 min
- Add the parts. Add all the parts for the total time.36 min + 1 h + 6 min = 1 h 42 min
- Write the answer. Give the journey time in hours and minutes.1 h 42 min
Check. Check: 1 h 42 min added to 14:24 gives 16:06.
Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.
Method. Add the top numbers and keep the bottom number. Simplify if you can.
- Add the top numbers. The bottom number stays the same, because the parts are the same size.3 + 2 = 5
- Keep the bottom number 8. The total is counted in the same parts.5/8
- Write the answer. This is the simplest form.5/8
Check. Check: 5/8 is equal to 5/8.
Watch out. Do not add the bottom numbers too. 2/8 + 3/8 is 5/8, not 5/16.
Method. A zero at the end of a decimal does not change its value.
- Add a zero at the end. Adding a zero after the last digit does not change the value.4.8 = 4.80
- Compare the two numbers. The tenths digit and the zero in the hundredths are both empty places.4.80 = 4.8
- Write the answer. They are equal; the zero only shows that there are no hundredths.4.80
Check. Check: 48/10 = 480/100.
Watch out. 0.5 and 0.50 are equal. The zero at the end does not make the number bigger.
Method. Look at the digit after the place you are rounding to, then decide.
- Look at the hundredths digit. This digit decides whether to round up or down.The digit is 1
- Decide. 5 or more: round up. 4 or less: round down.1 is 4 or less, so round down
- Write the rounded number. Make the digits after the rounding place zero, or leave them out.4.8
Check. Check: 4.8 is the closest number with the right number of places to 4.814.
Watch out. Round up only on a 5 or more. Do not drop the zero from the tenths when rounding to tenths.
Method. Hundredths have two places after the decimal point.
- Look at the bottom number. The bottom number 100 means hundredths: two places after the point.59/100
- Write the digits in the two places. 59 hundredths: a 0 in the tenths place, then 59 in the hundredths place.0.59
- Write the answer. The two digits after the point are hundredths.0.59
Check. Check: 0.59 is 59 hundredths, which is 59/100.
Watch out. Keep both places. 7/100 is 0.07, not 0.7.
Method. Multiply the measure by the number of items, then change to mixed units.
- Work out the total in the smallest unit. Each one is 191 cm.191 cm × 3 = 573 cm
- Change back to m and cm. Share the cm into groups of 100.573 cm = 5 m 73 cm
- Write the answer. Give the total in mixed units.5 m 73 cm
Check. Check: 573 ÷ 3 = 191.
Watch out. Multiply in the small unit, then change back at the end.
Method. Subtract the top numbers and keep the bottom number. Simplify if you can.
- Subtract the top numbers. The bottom number stays the same.2 - 1 = 1
- Keep the bottom number 4. The parts are the same size, so the bottom number does not change.1/4
- Write the answer. This is the simplest form.1/4
Check. Check: 1/4 + 1/4 gives 2/4.
Watch out. Do not subtract the bottom numbers. 7/8 - 3/8 is 4/8, which is 1/2.
Method. Multiply by 1,000 to change kilometres into metres.
- Use the rule. 1 kilometre is 1,000 metres.1 km = 1,000 m
- Multiply the kilometres by 1,000. Each kilometre is 1,000 metres.4 × 1,000 = 4,000
- Write the answer with the unit. The unit is metres.4,000 m
Check. Check: 4,000 ÷ 1,000 = 4.
Watch out. Going to a smaller unit makes the number bigger. Multiply.
Method. Subtract the top numbers and keep the bottom number. Simplify if you can.
- Subtract the top numbers. The bottom number stays the same.4 - 3 = 1
- Keep the bottom number 5. The parts are the same size, so the bottom number does not change.1/5
- Write the answer. This is the simplest form.1/5
Check. Check: 1/5 + 3/5 gives 4/5.
Watch out. Do not subtract the bottom numbers. 7/8 - 3/8 is 4/8, which is 1/2.
Method. Change both measures to the same unit, ml, then add, then change back.
- Change both to ml. 1 l = 1,000 ml.2 l 703 ml = 2,703 ml, and 916 ml = 916 ml
- Add the ml. Work with the same unit.2,703 + 916 = 3,619 ml
- Change back to l and ml. Share the ml into groups of 1,000.3,619 = 3 l and 619 ml
- Write the answer. Give the answer in mixed units, as the question was.3 l 619 ml
Check. Check: 3 l 619 ml - 916 ml gives 2 l 703 ml again.
Watch out. Keep the unit with each number. A total of 1,000 ml is 1 l.
Method. Multiply the measure by the number of items, then change to mixed units.
- Work out the total in the smallest unit. Each one is 3,557 g.3,557 g × 3 = 10,671 g
- Change back to kg and g. Share the g into groups of 1,000.10,671 g = 10 kg 671 g
- Write the answer. Give the total in mixed units.10 kg 671 g
Check. Check: 10,671 ÷ 3 = 3,557.
Watch out. Multiply in the small unit, then change back at the end.
Method. Multiply by 10 to change cm into mm.
- Use the rule. 1 cm is 10 mm.1 cm = 10 mm
- Multiply the cm by 10. Each cm has 10 mm.14 × 10 = 140
- Write the answer with the unit. The unit is mm.140 mm
Check. Check: 140 ÷ 10 = 14.
Watch out. A smaller unit gives a bigger number. Multiply by 10.
Method. Divide by the bottom number to find one part, then multiply by the top number.
- Find one 5th of 15. Share 15 into 5 equal parts.15 ÷ 5 = 3
- Take 2 of those parts. The top number tells us how many parts.2 × 3 = 6
- Write the answer. Keep the unit from the question.6 cm
Check. Check: 3 × 5 = 15, and 2 parts is 6.
Watch out. Divide first, then multiply. Do not multiply by the bottom number.
Method. Write the whole number, then one digit for the tenths and two digits for the hundredths.
- Write the whole number first. This is the part before the decimal point.2
- Write the tenths and the hundredths after the point. 1/10 is one place, and 1/100 is two places.2.11
- Write the answer. Check that each digit is in the right place.2.11
Check. Check: 2.11 = 2 + 0.1 + 0.01, when h is a single digit.
Watch out. Use two places for hundredths. The hundredths digit is the second place after the point.
Method. With the same denominator, compare the numerators.
- Look at the bottom numbers. Both fractions have the same bottom number, so the parts are the same size.Both are 8ths
- Compare the top numbers. With the same size of part, the bigger top number is the bigger fraction.1 and 4
- Choose the greater fraction. The fraction with more parts is greater.4/8
Check. Check: 4 parts is more than 1 parts of the same size.
Watch out. Do not compare the bottom numbers. The bigger the bottom number, the smaller each part.
Method. Hundredths have two places after the decimal point.
- Look at the bottom number. The bottom number 100 means hundredths: two places after the point.46/100
- Write the digits in the two places. 46 hundredths: a 0 in the tenths place, then 46 in the hundredths place.0.46
- Write the answer. The two digits after the point are hundredths.0.46
Check. Check: 0.46 is 46 hundredths, which is 46/100.
Watch out. Keep both places. 7/100 is 0.07, not 0.7.
Chapter summary
| Skill | Method |
|---|---|
| Numbers to a million | Value = digit × column value; round by looking one column to the right |
| Column methods | Work from the right; carry or exchange; check with the inverse |
| Times tables and division | Use the 11 and 12 patterns; short division with a remainder written after the answer |
| Fractions and decimals | Same denominator: add or subtract the top numbers; decimals line up on the point |
| Measures, time and money | Change to the same unit; count on across the hour or midnight; keep two places for pence |
Can you…?
- I can say the value of each digit in a number to 1,000,000, and round and compare numbers
- I can add and subtract whole numbers to a million in columns
- I can recall the times tables to 12 times 12, and use the 11 and 12 patterns
- I can multiply a two-digit number by a one-digit number, and divide with remainders
- I can add and subtract fractions with the same denominator, and write mixed numbers
- I can work with decimals to hundredths, metric measures, perimeter, time and money
Key terms
- column
- a place in a number, such as hundreds or tens
- remainder
- the amount left over in a division
- perimeter
- the distance all the way round a shape
- mixed number
- a whole number and a fraction, such as 1 1/4
Exercise 10Z Check-up
Non-calculatorMethod. Count in 11s to find 4 groups of 11. The order of the numbers does not matter.
- Count in 11s, 4 times. Each count adds one more group of 11.11, 22, 33, 44
- The last number we said is the answer. We counted 4 groups of 11.11 × 4 = 44
- Write the answer. The order of the two numbers does not change the answer.44
Check. Check: 4 × 11 is also 44.
Watch out. Learn the 11 times table in order, then say it in any order.
Method. Read the column, then multiply the digit by the value of that column.
- Find the thousands column. Count the columns from the right: ones, tens, hundreds and so on.The digit is 2
- Multiply the digit by the value of its column. Each place in the thousands column is worth 1,000.2 × 1,000 = 2,000
- Write the value. This is the value of the digit in this number, not just the digit.2,000
Check. Check: 2,000 is 2 groups of 1,000.
Watch out. Say the value, such as 70,000, not only the digit 7.
Method. Add the top numbers and keep the bottom number. Simplify if you can.
- Add the top numbers. The bottom number stays the same, because the parts are the same size.4 + 4 = 8
- Keep the bottom number 10. The total is counted in the same parts.8/10
- Simplify. Divide the top and bottom by the same number, which is 2.8/10 = 4/5
- Write the answer. This is the simplest form.4/5
Check. Check: 4/5 is equal to 8/10.
Watch out. Do not add the bottom numbers too. 2/8 + 3/8 is 5/8, not 5/16.
Method. Split 12 into 10 and 2, then add the two results.
- Split 12 into 10 and 2. Multiply each part by the number.12 × 12 = 10 × 12 + 2 × 12
- Work out each part. Both parts are facts we know.10 × 12 = 120, and 2 × 12 = 24
- Add the two parts. The total is the answer.120 + 24 = 144
- Write the answer. This is the answer to 12 times the number.144
Check. Check: 144 ÷ 12 = 12.
Watch out. Do not add 12 to the number only once. Work out both parts.
Method. Divide by the bottom number to find one part, then multiply by the top number.
- Find one 5th of 15. Share 15 into 5 equal parts.15 ÷ 5 = 3
- Take 3 of those parts. The top number tells us how many parts.3 × 3 = 9
- Write the answer. Keep the unit from the question.9 cm
Check. Check: 3 × 5 = 15, and 3 parts is 9.
Watch out. Divide first, then multiply. Do not multiply by the bottom number.
Method. Count in 11s to find 9 groups of 11. The order of the numbers does not matter.
- Count in 11s, 9 times. Each count adds one more group of 11.11, 22, 33, 44, 55, 66, 77, 88, 99
- The last number we said is the answer. We counted 9 groups of 11.11 × 9 = 99
- Write the answer. The order of the two numbers does not change the answer.99
Check. Check: 9 × 11 is also 99.
Watch out. Learn the 11 times table in order, then say it in any order.
Method. Add the columns from the right. Carry any ten into the next column on the left.
- Add the ones column. Write 2 and carry 1 to the tens column.4 + 8 = 12
- Add the tens column. Write 2 and carry 1 to the hundreds column.6 + 5 + 1 carried = 12
- Add the hundreds column. Write 2 and carry 1 to the thousands column.2 + 9 + 1 carried = 12
- Add the thousands column. Write 0 and carry 1 to the ten thousands column.0 + 9 + 1 carried = 10
- Add the ten thousands column. Write 7 in the ten thousands column.3 + 3 + 1 carried = 7
- Add the hundred thousands column. Write 1 in the hundred thousands column.1 + 0 = 1
- Write the answer. Put the digits together, with commas between groups of three.170,222
Check. Check: 170,222 - 39,958 = 130,264.
Watch out. Carry the 1 into the next column. Do not forget it, and do not write it as a digit in its own column.
Method. Divide by 10 to find the whole cm; the remainder is the mm.
- Use the rule. 1 cm is 10 mm.1 cm = 10 mm
- Share 153 mm into groups of 10. Each group is one cm.153 ÷ 10 = 15 r 3
- Write the answer. 15 whole cm and the mm left over.15 cm 3 mm
Check. Check: 15 × 10 + 3 = 153.
Watch out. Use a space between the two parts, and the unit after each: 15 cm 3 mm.
Method. Subtract each column from the right. Exchange 1 from the column on the left when the top digit is too small.
- Subtract the ones column. 9 is at least 4, so subtract directly.9 - 4 = 5
- Subtract the tens column. 1 is at least 1, so subtract directly.1 - 1 = 0
- Subtract the hundreds column. 1 is less than 3, so exchange 1 thousands for 10 hundreds.11 - 3 = 8
- Subtract the thousands column. 6 is less than 8, so exchange 1 ten thousands for 10 thousands.16 - 8 = 8
- Subtract the ten thousands column. 2 is less than 8, so exchange 1 hundred thousands for 10 ten thousands.12 - 8 = 4
- Subtract the hundred thousands column. 1 is at least 0, so subtract directly.1 - 0 = 1
- Write the answer. Read the digits from the left, and put commas in.148,805
Check. Check: 88,314 + 148,805 = 237,119.
Watch out. When you exchange across zeros, change each zero to 9 as you pass it. Do not leave a zero in the middle.
Method. Count in 11s to find 8 groups of 11. The order of the numbers does not matter.
- Count in 11s, 8 times. Each count adds one more group of 11.11, 22, 33, 44, 55, 66, 77, 88
- The last number we said is the answer. We counted 8 groups of 11.11 × 8 = 88
- Write the answer. The order of the two numbers does not change the answer.88
Check. Check: 8 × 11 is also 88.
Watch out. Learn the 11 times table in order, then say it in any order.
Total 39 marks. Allow about 39 minutes.
Exercise 10X Level 5 check
Non-calculatorMethod. Work out each missing side, then add all the sides of the shape.
- Find the missing sides. Missing sides come from the sides that are given: take away the shorter part.step = 5 - 2 = 3 cm; right side = 8 - 2 = 6 cm
- List all six sides. The perimeter is the distance all the way round.2 + 6 + 3 + 2 + 5 + 8 cm
- Add the sides. Add all the lengths together.26 cm
- Write the perimeter. Give the answer with the unit cm.26 cm
Check. Check: the perimeter of a shape like this is twice the width plus twice the height: 2 × (5 + 8) = 26 cm.
Watch out. Do not add only the sides you can see. Every side counts, including the ones you worked out.
Method. Work out each missing side, then add all the sides of the shape.
- Find the missing sides. Missing sides come from the sides that are given: take away the shorter part.step = 12 - 10 = 2 cm; right side = 5 - 3 = 2 cm
- List all six sides. The perimeter is the distance all the way round.10 + 2 + 2 + 3 + 12 + 5 cm
- Add the sides. Add all the lengths together.34 cm
- Write the perimeter. Give the answer with the unit cm.34 cm
Check. Check: the perimeter of a shape like this is twice the width plus twice the height: 2 × (12 + 5) = 34 cm.
Watch out. Do not add only the sides you can see. Every side counts, including the ones you worked out.
Method. Look at the digit to the right of the tens column, then decide.
- Look at the ones digit. This digit decides whether to round up or down.The ones digit is 7
- Decide: round up or down. 5 or more: round up. 4 or less: round down.7 is 5 or more, so round up
- Write the rounded number. Replace the digits after the tens column with zeros.117,170
Check. Check: 117,170 is a multiple of 10 and is the closest one to 117,167.
Watch out. Round up only when the next digit is 5 or more. Do not round up on a 4.
Method. Add the costs, then subtract the total from the money at the start.
- Add the two costs. Add the pounds and the pence together.£4.93 + £1.16 = £6.09
- Take the total away from the money Sam has. Subtract the total cost.£10.29 - £6.09 = £4.20
- Write the answer. Give the amount left with the pound sign.£4.20
Check. Check: £4.20 + £6.09 = £10.29.
Watch out. Keep the pence in two places: £0.85 and £2.40, not £0.85 and £2.4.
Method. The first digit after the point is the number of tenths.
- Find the tenths digit. It is the first digit after the decimal point.The digit is 0
- Write its value. 0 tenths is 0/10.0/10 = 0.0
- Write the answer. The value of the tenths digit is 0.1 times the digit.0.0
Check. Check: the first digit after the point is 0, so the value is 0/10 = 0.0.
Watch out. Read the digit after the point as tenths. 4 tenths is 0.4, not 4.
Method. Only the ten thousands digit changes when we add or take away 10,000.
- Look at the ten thousands digit. Adding or taking away 10,000 changes this digit by one.The ten thousands digit is 8
- Change that digit by one. Carry or borrow if the digit goes past 9 or below 0.8 - 1 = 7
- Write the answer. All the other digits stay the same.875,464
Check. Check: 875,464 add 10,000 gives back 885,464.
Watch out. Do not change the thousands digit. 10,000 is not 1,000.
Method. Count in 12s to find 7 groups of 12. The order of the numbers does not matter.
- Count in 12s, 7 times. Each count adds one more group of 12.12, 24, 36, 48, 60, 72, 84
- The last number we said is the answer. We counted 7 groups of 12.12 × 7 = 84
- Write the answer. The order of the two numbers does not change the answer.84
Check. Check: 7 × 12 is also 84.
Watch out. Learn the 12 times table in order, then say it in any order.
Method. The second digit after the point is the number of hundredths.
- Find the hundredths digit. It is the second digit after the decimal point.The digit is 0
- Write its value. 0 hundredths is 0/100.0/100 = 0.00
- Write the answer. The value is a decimal with the digit in the second place.0.00
Check. Check: in 7.10 the second digit after the point is 0, so the value is 0/100 = 0.00.
Watch out. The value is 0.0 with the digit after it: 0.07, not 0.7.
Method. Multiply the hours by 60 to change them into minutes.
- Use the rule. There are 60 minutes in 1 hour.1 h = 60 min
- Multiply the hours by 60. Each hour has 60 minutes.4 × 60 = 240
- Write the answer. The unit is minutes.240 minutes
Check. Check: 240 ÷ 60 = 4.
Watch out. Going from hours to minutes gives a bigger number. Multiply by 60.
Method. Compare the digits from the left: whole numbers, then tenths, then hundredths.
- Compare the whole numbers. The bigger whole number is the bigger decimal.1 and 1
- Compare the tenths. If the whole numbers match, the tenths decide.8 and 1 tenths
- Compare the hundredths. If the tenths also match, the hundredths decide.7 and 3 hundredths
- Choose the greater number. This is the number with the larger digit in the first place they differ.1.87
Check. Check: 1.87 is 187 hundredths and 1.13 is 113 hundredths.
Watch out. Do not think 0.45 is bigger than 0.5 because 45 is bigger than 5. Compare the tenths first.
Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.
- Count the minutes to the next hour. Go from the start time to the next full hour.08:45 to 09:00 is 15 min
- Count the whole hours. Count each full hour after that.0 whole hours
- Count the minutes after the last whole hour. Count on to the arrival time.58 min
- Add the parts. Add all the parts for the total time.15 min + 0 h + 58 min = 1 h 13 min
- Write the answer. Give the journey time in hours and minutes.1 h 13 min
Check. Check: 1 h 13 min added to 08:45 gives 09:58.
Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.
Method. Add the columns from the right. Carry any ten into the next column on the left.
- Add the ones column. Write 8 in the ones column.2 + 6 = 8
- Add the tens column. Write 7 and carry 1 to the hundreds column.9 + 8 = 17
- Add the hundreds column. Write 4 and carry 1 to the thousands column.4 + 9 + 1 carried = 14
- Add the thousands column. Write 3 in the thousands column.1 + 1 + 1 carried = 3
- Add the ten thousands column. Write 8 in the ten thousands column.3 + 5 = 8
- Add the hundred thousands column. Write 4 in the hundred thousands column.3 + 1 = 4
- Write the answer. Put the digits together, with commas between groups of three.483,478
Check. Check: 483,478 - 151,986 = 331,492.
Watch out. Carry the 1 into the next column. Do not forget it, and do not write it as a digit in its own column.
Method. Multiply the number in each group by the number of groups, or the amount by the number of times.
- Find the cost of one pen and the number of pens. Each pen costs the same amount.80p for each of 4 pens
- Multiply the cost of one pen by the number of pens. The total cost is the cost of each times the number.80p × 4 = 320p
- Write the answer. Give the cost in pence, as the question asks.320p
Check. Check: 320p is more than the first number, because we multiplied by 4.
Watch out. Check the units: the answer should be in the same unit as the question (pencils, pence, stamps).
Method. Compare the whole numbers, then the tenths, then the hundredths.
- Compare the whole numbers. Put the smallest whole number first.5, 7, 1, 6
- Compare the tenths and hundredths. Use the next places to put the rest in order.5.80, 7.02, 1.19, 6.00
- Write the list smallest first. Check each pair in order.1.19, 5.80, 6.00, 7.02
Check. Check: each number is smaller than the one after it.
Watch out. Do not order by the number of digits. Compare the places from the left.
Method. Find the total of all the items, then take it from the money paid.
- Work out the cost of the cups. Multiply the price by the number of cups.4 × £1.15 = £4.60
- Add the cost of the cake. Add all the items to find the total.£4.60 + £1.32 = £5.92
- Work out the change. Change is what is left from the money paid.£10.00 - £5.92 = £4.08
- Write the answer. Give the change with the pound sign.£4.08
Check. Check: £5.92 + £4.08 = £10.00.
Watch out. Add all the items before you take anything away.
Method. Use the inverse operation to find the missing number.
- Think about the total. The missing number is what is left when we take the known number away.659,059 - 442,385
- Subtract to find the missing number. Use the column method.659,059 - 442,385 = 216,674
- Check by adding. The missing number and the known number must make the total.442,385 + 216,674 = 659,059
- Write the missing number. This is the number in the box.216,674
Check. Check: put 216,674 into the sum and it works.
Watch out. To find a missing number in a sum, subtract. To find it in a difference, add.
Method. Multiply the number of groups by the number in each group.
- Find the number of bags and the number in each. Multiply the number of equal groups by the size of each group.2 bags of 6
- Work out the multiplication. Use the times table for this number.2 × 6 = 12
- Write the answer. This is the total number of sweets.12
Check. Check: 12 ÷ 2 = 6, so each bag has 6.
Watch out. If you are not sure of the fact, count in the times table, one group at a time.
Method. Write the whole number, then a decimal point, then the tenths digit.
- Write the whole number first. This is the part before the decimal point.7
- Write the tenths after a decimal point. 4/10 is 4 tenths, so the digit 4 goes after the point.7.4
- Write the answer. A decimal point separates the whole number from the tenths.7.4
Check. Check: 4/10 is 0.4, and 7 + 0.4 = 7.4.
Watch out. The tenths digit is one place after the decimal point.
Method. More than one whole: add the top numbers, then write the whole ones out.
- Add the top numbers. Keep the bottom number the same.3 + 5 = 8
- Write the total. 8 parts of size 1/6.8/6
- Write as a mixed number. There are 1 whole one and 1/3 left over.4/3 = 1 1/3
- Write the answer. This is the answer in its simplest form.1 1/3
Check. Check: 1 1/3 is more than 1, as 8/6 is more than 6/6.
Watch out. A top number bigger than the bottom is more than one whole. Write it as a mixed number.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 8. Write 8 in the ones column and carry 4 to the tens column.6 × 8 = 48
- Multiply the tens digit by 8. Write 8 in the tens column and carry 6 to the hundreds column.8 × 8 = 64, plus 4 carried = 68
- Write the carried number in front. The carried number is the next digit on the left.6 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.688
Check. Check: 688 ÷ 8 = 86.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.