Ross MackellUK-qualified primary teacher · 8 min read

Your child brings home their maths homework and, instead of the division you remember, there's a long column of numbers being taken away, with little notes in brackets down the side. You ask what they're doing. They say "chunking". You nod, and quietly hope they don't ask you for help.

Chunking is one of the most sensible methods in primary maths, and once you see what it's really doing, it's easy to help with. It also explains why division works in a way the bus stop method never does, which is exactly why many schools teach it first.

I'm Ross, a UK-qualified primary teacher with over ten years in the classroom. In this guide I'll show you what chunking is, how to do it step by step, how it handles remainders and bigger numbers, the mistakes I see most often, and a 10-minute practice routine with answers.

What your child needs first

Chunking is really three skills working together. Your child needs:

• Times tables. Every chunk is a times table fact. If 6 × 4 is a struggle, chunking will be too. Start here: how to learn times tables fast.
• Multiplying by 10 and 100. The big chunks (10 lots, 20 lots, 100 lots) are what make chunking quick. See multiplying and dividing by 10, 100 and 1000.
• Subtraction. Every step is a take-away, often a 3-digit one. If that's shaky, have a look at column subtraction first.

Chunking isn't named in the national curriculum, but it's widely used in Years 4 and 5 as a stepping stone. By the end of Year 6, children are expected to divide numbers up to 4 digits by a 2-digit number using a formal written method, and chunking is how a lot of them get there.

What is the chunking method?

Division can mean sharing ("share 96 sweets between 4 children") or grouping ("how many groups of 4 are there in 96?"). Chunking uses the grouping idea. Instead of counting groups of 4 one at a time, you take them away in big handfuls that you already know.

Here's 96 split into two chunks. The first chunk is 20 groups of 4. The second is 4 more groups of 4.

That's the whole method. You keep taking away chunks you know until nothing (or just a little remainder) is left, then add up the number of groups.

Chunking step by step

Example 1: 96 ÷ 4

1. Ask: what's a big, easy chunk of 4s? 10 × 4 = 40 is easy, but 20 × 4 = 80 is even better, and it's still less than 96.
2. Take it away: 96 − 80 = 16. Write "(20 × 4)" next to it so you don't lose track.
3. What's left is 16. That's 4 × 4. Take it away: 16 − 16 = 0.
4. Add up the groups in the brackets: 20 + 4 = 24.

This is how your child will set it out in their book: the number at the top, each chunk taken away underneath, and the number of groups written in brackets on the right.

Example 2: 156 ÷ 6

Here's where children have a choice, and it's a really useful conversation to have with them. A careful child might take away 10 lots at a time:

That's completely correct. But a more confident child spots that 20 × 6 = 120 fits into 156, and gets there in fewer steps:

Both are right. The bigger the chunks, the fewer the steps, and the fewer chances to make a subtraction slip. When your child is ready, nudge them with: "Is there a bigger chunk you could have used?"

Chunking with remainders

Not every number divides exactly. With chunking, a remainder simply means you stop when what's left is smaller than the number you're dividing by.

Example 3: 100 ÷ 7

1. Big chunk: 10 × 7 = 70. 100 − 70 = 30.
2. Next chunk: 4 × 7 = 28 (5 × 7 = 35 is too big). 30 − 28 = 2.
3. 2 is smaller than 7, so you can't take away another group. Stop. 2 is the remainder.
4. Add the groups: 10 + 4 = 14.

A great habit is checking the answer by multiplying back: 14 × 7 = 98, and 98 + 2 = 100. If it doesn't land back on the starting number, something has gone wrong.

Bigger numbers and 2-digit divisors

This is where chunking really earns its place. Dividing by a 2-digit number like 18 is hard to do in your head, so the trick is to write a short list of easy facts down the side before you start.

Example 4: 432 ÷ 18

First, the facts list. Every one of these is quick to work out from the one above or below it:

1. The biggest chunk that fits into 432 is 20 × 18 = 360. 432 − 360 = 72.
2. Is there a fact for 72? 2 × 18 = 36, so 4 × 18 = 72. 72 − 72 = 0.
3. Add the groups: 20 + 4 = 24.

The facts list is the secret. It turns a scary division into a few easy look-ups and subtractions. This is exactly the same thinking your child will use later in formal long division.

Chunking or the bus stop method?

Parents often ask me which method their child should be using. Here's how I think about it:

• Chunking builds understanding. Children can see that division is just taking away equal groups, and they can use any chunk they're confident with. It's forgiving: a small chunk is slower, but never wrong.
• The bus stop method (short division) is faster and more compact for dividing by a single digit. Most schools expect children to be using it by Year 5. Here's my step-by-step guide to the bus stop method.
• Long division is the formal method for 2-digit divisors in Year 6. Many schools teach a version of it that uses the same facts list you saw above. See long division step by step.

My advice: if your child's school is teaching chunking, go with it. Don't switch to your own method at home, because two methods at once is a recipe for confusion. If they're secure with chunking and finding it slow, that's the moment to move on to the bus stop method.

4 common mistakes and how to fix them

Mistake 1: Adding up the numbers instead of the groups

For 96 ÷ 4, your child adds 80 + 16 and gets 96. That's just the number they started with!

The fix: the answer always comes from the brackets, never from the numbers taken away. I tell children: "The answer lives in the brackets." Some like to circle the bracket numbers as they go.

Mistake 2: Chunks that are far too small

Taking away one 4 at a time from 96 means 24 subtractions. It's not wrong, but it's exhausting and full of chances to slip up.

The fix: always write the facts list first (1×, 2×, 5×, 10×, 20×) and ask "What's the biggest chunk that fits?" before each step.

Mistake 3: Stopping too early

For 100 ÷ 7 your child takes away 70, gets 30, and writes "10 r 30". But 30 still has plenty of 7s in it.

The fix: one question every time: "Is what's left smaller than the number I'm dividing by?" If not, keep going. A remainder can never be bigger than (or equal to) the divisor.

Mistake 4: The subtraction goes wrong

Plenty of children get the method right and then make a slip in 432 − 360.

The fix: this is a subtraction problem, not a division problem. Multiplying back at the end catches it. If it keeps happening, spend a week on column subtraction.

A 10-minute practice routine

Same three steps I use for every skill: watch, copy, practise.

1. Watch: do one yourself, out loud. "96 divided by 4. What's a big chunk of 4s I know? 20 fours are 80. Take it away, that leaves 16. 16 is 4 fours. So 20 and 4 is 24."
2. Copy: your child does a very similar one, saying each step out loud.
3. Practise: three or four on their own, then check together by multiplying back.

Work down the table over a week or two. Only move on when they're getting three in a row right. Ten minutes, a few times a week, is plenty.

Frequently asked questions

What is the chunking method in division?

Chunking is a written method for division where you repeatedly subtract multiples (chunks) of the divisor from the number you're dividing, then add up how many groups you subtracted. For example, 96 ÷ 4: subtract 80 (20 × 4), then 16 (4 × 4), so the answer is 20 + 4 = 24.

What year do children learn chunking?

Chunking isn't named in the national curriculum for England, but many schools use it in Years 4 and 5 as a bridge to formal written methods. By Year 6, children are expected to use formal short and long division, and some schools continue to use chunking for dividing by 2-digit numbers.

Is chunking the same as long division?

Not quite, but they're closely related. Both work by taking away multiples of the divisor. Long division is a more compact, formal layout that works through the number digit by digit, while chunking lets children take away any chunk they're confident with. Some schools teach long division with a facts list, which is very similar to chunking.

How do you do chunking with remainders?

Keep taking away chunks until what's left is smaller than the number you're dividing by. That leftover amount is the remainder. For 100 ÷ 7: take away 70 (10 × 7), leaving 30, then 28 (4 × 7), leaving 2. The answer is 14 remainder 2.

Should I teach my child chunking or the bus stop method?

Use whichever method your child's school is teaching, so they aren't juggling two methods at once. Chunking is great for understanding and for 2-digit divisors. Once your child is secure and finding it slow, the bus stop method is quicker for dividing by a single digit.

Sources and further reading

• Department for Education, National curriculum in England: mathematics programmes of study (multiplication and division, Years 4 to 6)
• Standards and Testing Agency, Key stage 2 mathematics test framework
• Ross Mackell, Teacher's Perspective on YouTube