Ross MackellUK-qualified primary teacher · 8 min read

Ask your child to work out 6.24 ÷ 3. A lot of children write 2.8. Some write 208. The answer is 2.08, and the difference between those answers is one small dot and one small zero.

Dividing decimals is a Year 6 skill that turns up on the SATs arithmetic paper every year. It looks scary to children because of the decimal point, but here's the good news: if your child can already do short division with whole numbers, they're about 90% of the way there. The decimal point just needs to go in the right place.

I'm Ross, a UK-qualified primary teacher with over ten years in the classroom. In this guide I'll show you how to divide a decimal by a whole number, how to turn a remainder into a decimal, how to divide by a decimal, how it comes up in SATs, the mistakes I see most often, and practice questions with answers.

What your child needs first

Dividing decimals is built on three things. If any of them are shaky, fix that first:

• Short division with whole numbers. The method is identical. If your child isn't confident with 96 ÷ 4 or 315 ÷ 7, start with the bus stop method step by step.
• Decimal place value. Your child needs to know that in 6.24, the 2 is 2 tenths and the 4 is 4 hundredths. What is place value? covers this.
• Times tables up to 12 × 12. Every step of division is really a times table question in reverse. 24 ÷ 3 is quick if your child knows 3 × 8 = 24.

In the national curriculum, children divide numbers by 10, 100 and 1000 in Year 5 (see multiplying and dividing by 10, 100 and 1000). In Year 6 they use written division methods where the answer has up to two decimal places, and they solve problems that need answers rounded to a set number of decimal places.

Dividing a decimal by a whole number

This is the one your child will meet most often in primary school. We use the bus stop, and we follow one rule before we start dividing.

Example 1: 8.4 ÷ 4

1. Write 8.4 inside the bus stop and 4 outside.
2. Put a decimal point on the answer line, directly above the decimal point in 8.4.
3. Divide the first digit: 8 ÷ 4 = 2. Write 2 above the 8.
4. Divide the next digit: 4 ÷ 4 = 1. Write 1 above the 4, after the decimal point.
5. The answer is 2.1.

Check it the quick way: 4 lots of 2 is 8, so the answer should be a little over 2. It is.

Example 2: 6.24 ÷ 3 (the one that catches everyone out)

1. Write 6.24 in the bus stop and put the decimal point in the answer straight above.
2. 6 ÷ 3 = 2. Write 2 above the 6.
3. Next digit: 2 ÷ 3. 3 doesn't go into 2, so write 0 above the 2 and carry the 2 across to make 24.
4. 24 ÷ 3 = 8. Write 8 above the 4.
5. The answer is 2.08.

That zero is the most important digit in the answer. Without it, your child gets 2.8, which is a completely different number. Every time the divisor doesn't go into a digit, a 0 must go on the answer line.

Example 3: 6.3 ÷ 7 (an answer less than 1)

1. Write 6.3 in the bus stop with the decimal point above.
2. 6 ÷ 7: 7 doesn't go into 6, so write 0 above the 6 and carry the 6 to make 63.
3. 63 ÷ 7 = 9. Write 9 above the 3.
4. The answer is 0.9.

Children are often surprised when the answer starts with 0. A quick estimate helps: 7 doesn't go into 6.3 even once, so the answer has to be less than 1.

Turning remainders into decimals

In Year 4 and Year 5, children write remainders like 23 ÷ 4 = 5 r3. In Year 6 they learn that the remainder can carry on into the decimal places instead. The trick is that you can add zeros after the decimal point without changing the number. 23 is the same as 23.00, and 7.5 is the same as 7.50.

Example 4: 23 ÷ 4

1. Write 23 as 23.00 in the bus stop, and put the decimal point in the answer above.
2. 2 ÷ 4: doesn't go, so write 0 (or leave it blank at the front) and carry the 2 to make 23.
3. 23 ÷ 4 = 5 remainder 3. Write 5 and carry the 3 to make 30.
4. 30 ÷ 4 = 7 remainder 2. Write 7 after the decimal point and carry the 2 to make 20.
5. 20 ÷ 4 = 5. Write 5. The answer is 5.75.

Example 5: 7.5 ÷ 6

1. Write 7.5 in the bus stop. 7 ÷ 6 = 1 remainder 1. Write 1 and carry the 1 to make 15.
2. 15 ÷ 6 = 2 remainder 3. Write 2 after the decimal point.
3. There's a remainder, so add a zero: 7.5 becomes 7.50. Carry the 3 to make 30.
4. 30 ÷ 6 = 5. The answer is 1.25.

Sometimes the division never ends. 10 ÷ 3 = 3.333... and the 3s go on forever. In Year 6 your child will usually be asked to round answers like this to one or two decimal places (3.3 or 3.33). If rounding feels wobbly, see how to round numbers.

Dividing by a decimal

Questions like 4.8 ÷ 0.6 are mostly a secondary school skill, but they come up in homework and in real life, so it's worth knowing. The method is: make the number you're dividing by into a whole number, and do the same thing to the other number so the answer doesn't change.

Example 6: 4.8 ÷ 0.6

1. 0.6 has one decimal place, so multiply both numbers by 10.
2. 4.8 × 10 = 48 and 0.6 × 10 = 6.
3. Now it's a times table fact: 48 ÷ 6 = 8.

Why is this allowed? Think of sharing sweets. 48 sweets shared between 6 people gives the same answer as 480 sweets shared between 60 people. As long as you do the same to both numbers, the answer stays the same.

Notice the answer, 8, is bigger than 4.8. That feels wrong to children because they've learned that division makes things smaller. Ask your child: "How many 0.6s fit into 4.8?" Because 0.6 is less than 1, lots of them fit.

Dividing decimals in SATs

Decimal division usually appears on the Year 6 SATs arithmetic paper in a few predictable ways. These are the types to practise:

In the reasoning papers, decimal division turns up in money and measures problems, such as "Four friends share a £9.60 bill equally. How much does each pay?" (£2.40). If your child isn't sure what the arithmetic paper looks like, read the guide to the Year 6 SATs arithmetic paper.

5 common mistakes and how to fix them

Mistake 1: Forgetting the decimal point

Your child works out 8.4 ÷ 4 and writes 21.

The fix: make placing the decimal point step one, every time, before any dividing happens. Then estimate: 8 ÷ 4 is about 2, so 21 can't be right.

Mistake 2: Leaving out the zero placeholder

Your child works out 6.24 ÷ 3 and writes 2.8.

The fix: every digit inside the bus stop gets a digit above it. If the number outside doesn't go, write a 0 above. Ask your child to check that the number of digits after the decimal point matches inside and on top.

Mistake 3: Stopping at a remainder

Your child writes 7.5 ÷ 6 = 1.2 r3.

The fix: once you're past the decimal point, remainders aren't allowed. Add a zero to the end of the number and carry the remainder across. Keep going until there's nothing left, or until the question tells you to round.

Mistake 4: Only moving one decimal point

Your child turns 4.8 ÷ 0.6 into 4.8 ÷ 6 and gets 0.8.

The fix: whatever you do to one number, you do to the other. Say it out loud together: "times both by 10". Then the sharing sweets check: does 48 ÷ 6 give the same answer as 4.8 ÷ 0.6? It does.

Mistake 5: Not checking if the answer makes sense

Your child works out 9.36 ÷ 3 and writes 31.2, and moves on.

The fix: estimate before and check after. 9 ÷ 3 is 3, so the answer must be about 3. You can also check with multiplication: 3.12 × 3 = 9.36. If it doesn't match, something went wrong. How to multiply decimals shows how.

Practice questions

Same three steps I use for every skill: watch, copy, practise. Do the first one out loud yourself, then let your child have a go at a similar one before they try the rest on their own. Cover the last column and ask your child to fill in the gaps.

Bonus question: work out 1 ÷ 3. What do you notice? (Answer: 0.333... The 3s go on forever, because there's always a remainder of 1.)

Ten minutes, a few times a week, is plenty. Only move on when they're getting three in a row right.

Frequently asked questions

How do you divide decimals step by step?

Set the calculation out as short division (the bus stop method). Put the decimal point in the answer directly above the decimal point in the number you are dividing, then divide one digit at a time from left to right, just like whole numbers. If there is a remainder at the end, add a zero and keep going.

How do you divide a decimal by a whole number?

Use short division and line up the decimal points. For 8.4 ÷ 4, write 8.4 inside the bus stop, put a decimal point straight above it, then work out 8 ÷ 4 = 2 and 4 ÷ 4 = 1. The answer is 2.1.

How do you divide by a decimal?

Turn the number you are dividing by into a whole number first. Multiply both numbers by 10 (or 100) so the answer stays the same. For 4.8 ÷ 0.6, multiply both by 10 to get 48 ÷ 6, which is 8.

What year do children learn to divide decimals?

In England, children divide by 10, 100 and 1000 in Year 5, and in Year 6 they use written division where the answer has up to two decimal places. Dividing by a decimal, such as 4.8 ÷ 0.6, is usually taught properly at secondary school.

Why does dividing by a decimal make the answer bigger?

Division asks how many groups of a number fit into another. 4.8 ÷ 0.6 asks how many 0.6s fit into 4.8. Because 0.6 is less than 1, lots of them fit, so the answer (8) is bigger than 4.8.

Sources and further reading

• Department for Education, National curriculum in England: mathematics programmes of study (number: multiplication and division, and fractions including decimals, Years 5 and 6)
• Standards and Testing Agency, Key stage 2 mathematics test framework
• Ross Mackell, Teacher's Perspective on YouTube