Grid multiplication method.How to do grid (box) multiplying.

Grid multiplication can be a very easy method to carry out. Just follow these steps:

First of all partition the number you are going to multiply (break the number down), for example, 38 can be partitioned to 30 and 8, or 126 can be partitioned to 100, 20 and 6.

Secondly, times each one of these partitioned numbers by the number you are multiplying by. A good tip is to cover up the zeros and add them onto the end of your answer!

Thirdly, add up all these results.

Example 1

Work out 37 ×  4.

Firstly, partition 37 to 30 and 7, and write these numbers along the top row of your grid as shown below:

×             30           7

4

Now all we need to do now is work out 30 × 4 and 7 × 4.

To work out 30 × 4, work out 3 ×4 and add a zero on to your answer (always ignore the zeros and add these on after)

So 3 × 4 = 12, so 30 × 4 = 120

Also work out 7 × 4 = 28.

You can fill these into your grid:

×             30           7

4            120         28

Now all we need to do next is add these two numbers up to give 148.

Example 2

Work out 417 × 5.

Firstly, partition 417 to 400, 10 and 7, and write these numbers along the top row of your grid as follows:

×             400         10           7

5

Now all you need to do now is work out 400 × 5, 10 × 5 and 7 × 5. Remember to cover up the zeros, and add them onto the end of your answer.

400 × 5 = 2000

10 × 5 = 50

7 × 5 = 35

So you can fill these into your grid:

×             400         10           7

5             2000       50           35

So adding these up gives an answer of 2085.

Top tips

If you are having trouble adding the numbers up at the end, then you can always carry out an addition method on your page. The easiest method is the carrying method.