Your child comes home, gets out their maths homework, and starts drawing boxes. Not doing the sum. Drawing boxes. If you learned to multiply by stacking the numbers and "carrying", this can look like a very long way round to answer 23 × 4.
It's called the grid method, and it isn't a gimmick. Done properly, it's one of the best ways I know to make a child actually understand what multiplication is doing, before they move on to the quicker written methods.
I'm Ross, a UK-qualified primary teacher with over ten years in the classroom. In this guide I'll show you exactly how the grid method works, why schools teach it, three worked examples, the mistakes I see most often, and a 10-minute routine you can use at the kitchen table, with answers.
Quick answer: the grid method is a way of multiplying by splitting each number into hundreds, tens and ones, multiplying each part in a box, then adding the boxes together. For 23 × 4: split 23 into 20 and 3. Then 20 × 4 = 80 and 3 × 4 = 12. Add them: 80 + 12 = 92.
In this guide
What your child needs first
The grid method doesn't replace times tables. It leans on them. Before you start, check your child is comfortable with:
- Times tables up to 10 × 10. Every box in the grid is a times table fact in disguise. If these are slow, start with how to learn times tables fast.
- Multiplying by 10 and 100. If they know 3 × 4 = 12, they need to see that 30 × 4 = 120. Here's my guide to multiplying and dividing by 10, 100 and 1000.
- Partitioning. Splitting 147 into 100, 40 and 7. If that's new, read what is partitioning first.
- Adding a few numbers together, usually with the column method once the numbers get big.
In the national curriculum, children start multiplying a 2-digit number by a 1-digit number in Year 3, and are expected to use a formal written method for 3-digit by 1-digit numbers by Year 4. The grid method is usually the bridge that gets them there.
What is the grid method?
The grid method (some schools call it the box method) is a way of breaking a big multiplication into small, easy ones. You split the numbers by place value, put each part on the edge of a grid, multiply to fill in each box, then add everything up.
Here's 23 × 4 as a grid:
| × | 20 | 3 |
|---|---|---|
| 4 | 80 | 12 |
Two boxes. Two easy facts. Then 80 + 12 = 92. That's the whole method.
Why do schools teach it?
Lots of parents ask me why their child can't just learn "the proper way". I get it. But here's what I've seen in the classroom over and over again.
When children jump straight into short multiplication, a lot of them learn it as a set of steps to copy: multiply, carry, add the little number. It works, until they forget a step. Then they have no idea whether their answer is sensible, because they never understood why the steps work.
The grid method shows them. 23 × 4 really is 20 lots of 4 plus 3 lots of 4. When a child can see that, the short method stops being magic and starts making sense. It's the same reason I explain in why maths is taught differently now: understanding first, speed second.
The trick is not to stay on it forever. More on that below.
The grid method step by step: 3 worked examples
Example 1: 23 × 4 (2-digit × 1-digit)
- Partition 23 into 20 and 3. Write them across the top. Write 4 down the side.
- Multiply each box: 20 × 4 = 80. 3 × 4 = 12.
- Add the boxes: 80 + 12 = 92.
For 20 × 4, I teach children to say "2 times 4 is 8, but it's 2 tens, so it's 8 tens: 80." Saying it out loud is what stops the most common mistake (see Mistake 1).
Example 2: 147 × 6 (3-digit × 1-digit)
| × | 100 | 40 | 7 |
|---|---|---|---|
| 6 | 600 | 240 | 42 |
- Partition 147 into 100, 40 and 7.
- Multiply: 100 × 6 = 600. 40 × 6 = 240. 7 × 6 = 42.
- Add: 600 + 240 + 42 = 882.
Once there are three or more boxes, I get children to add them in a column underneath rather than in their heads. It's much harder to lose a number that way.
Example 3: 34 × 26 (2-digit × 2-digit)
This is where the grid method really earns its place. Both numbers get partitioned, so you get four boxes.
| × | 30 | 4 |
|---|---|---|
| 20 | 600 | 80 |
| 6 | 180 | 24 |
- Partition 34 into 30 and 4 (across the top), and 26 into 20 and 6 (down the side).
- Multiply each box: 30 × 20 = 600. 4 × 20 = 80. 30 × 6 = 180. 4 × 6 = 24.
- Add all four: 600 + 80 + 180 + 24 = 884.
30 × 20 trips a lot of children up. Teach it as "3 × 2 = 6, and there are two zeros, so 600." Then check it the long way: 30 lots of 20 is 600. It is.
The grid method only works if the facts underneath are secure. Times tables, place value and written methods are all part of the 15 core skills every child aged 7 to 11 needs.
My free guide for parents shows all 15 core skills in order, so you can see exactly which one is holding your child back.
Get the free 15 Core Skills guide →When to move on to short multiplication
The grid method is a stepping stone, not the destination. It takes up a lot of space and it's slow, and in the Year 6 SATs arithmetic paper, time matters. Children who are still drawing grids for 4-digit numbers in Year 6 are usually the ones who run out of time.
I'd move your child on when they can:
- Do a 2-digit × 1-digit grid accurately, three times in a row, without help.
- Explain why 40 × 6 is 240, not 24.
- Add up the boxes without mistakes.
Then show them that short multiplication is doing exactly the same thing, just squashed into one line. The "carried" number in short multiplication is just the tens from one of the boxes. When children see that link, the jump is easy. For 2-digit × 2-digit, the next step is long multiplication.
4 common mistakes and how to fix them
Mistake 1: Losing the zeros
Your child writes 20 × 4 = 8. They've done the times table fact and forgotten the 2 is really 20.
The fix: make them say it out loud. "2 tens times 4 is 8 tens, which is 80." Then ask: "Is 20 × 4 bigger or smaller than 4 × 4?" They'll see 8 can't be right.
Mistake 2: Partitioning into digits, not values
They split 23 into 2 and 3, instead of 20 and 3. Then 2 × 4 + 3 × 4 = 20. Way too small.
The fix: this is a place value gap, not a multiplication gap. Spend a few sessions on place value first. It will fix far more than this one mistake.
Mistake 3: Getting the boxes right, then the adding wrong
Every box is correct, then 600 + 240 + 42 becomes 842. It's painful to watch, and it's very common.
The fix: always add the boxes in a column, lined up by place value. Never in their head once there are three or more.
Mistake 4: Staying on the grid too long
Some children love the grid because it feels safe. That's fine in Year 3 and 4. In Year 6 it costs them marks.
The fix: once they're accurate, do every question twice: once with the grid, once with short multiplication. When both answers match a few times in a row, they'll start trusting the quicker method.
A 10-minute practice routine
Same three steps I use for every skill: watch, copy, practise.
- Watch: do one yourself, out loud. "23 is 20 and 3. 20 times 4 is 80. 3 times 4 is 12. 80 add 12 is 92."
- Copy: your child does a very similar one, saying each step out loud.
- Practise: three or four on their own. Check the answers together.
| Question | What it practises | Answer |
|---|---|---|
| 32 × 3 | 2 boxes, no exchanging | 96 |
| 45 × 6 | Boxes that add over 100 | 270 |
| 18 × 7 | Harder times table fact | 126 |
| 124 × 5 | 3 boxes | 620 |
| 236 × 4 | 3 boxes, bigger adding | 944 |
| 23 × 14 | First 2-digit × 2-digit | 322 |
| 42 × 35 | 4 boxes, tens × tens | 1,470 |
Work down the table over a week or two, not all in one night. Only move on when they're getting three in a row right. Ten minutes, a few times a week, is plenty.
Keep going
Frequently asked questions
What is the grid method in maths?
The grid method is a way of multiplying where you split each number into hundreds, tens and ones, multiply each part in a separate box of a grid, then add all the boxes together. For example, 23 × 4 = (20 × 4) + (3 × 4) = 80 + 12 = 92.
What year do children learn the grid method?
Most UK schools introduce the grid method in Year 3 or Year 4, when children start multiplying 2-digit and 3-digit numbers by 1-digit numbers. Many schools use it again in Year 5 for 2-digit by 2-digit multiplication before moving on to long multiplication.
Is the grid method the same as the box method?
Yes. The grid method and the box method are two names for the same thing. Some schools also call it the area method, because the grid works like finding the area of a rectangle split into parts.
Can you use the grid method in the SATs?
Yes, a correct answer gets full marks whatever method your child uses. But on the 2-mark long multiplication questions, if the answer is wrong, a method mark is only given for a formal method like long multiplication, not the grid. That's why it's worth moving children on to the formal method by Year 6.
Is the grid method better than short multiplication?
Neither is better. The grid method is better for understanding why multiplication works. Short multiplication is quicker and takes up less space. Children should learn the grid method first, then move on to short multiplication once they're accurate.
Get all 15 core skills in one place
The grid method is one step on the road to confident multiplication. The 15 core skills are the written methods and facts every child aged 7 to 11 needs to master to succeed in maths.
My free guide for parents shows all 15, in order, so you can see exactly where your child is and what comes next.
Get the free 15 Core Skills guide →Sources and further reading
- Department for Education, National curriculum in England: mathematics programmes of study (multiplication in Years 3 and 4)
- Standards and Testing Agency, Key stage 2 mathematics test framework
- Ross Mackell, Teacher's Perspective on YouTube
