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Look at the fractions section for help with how to multiply fractions or the decimals section for guidance on multiplying decimals.
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How To Multiply Numbers # 1

By Subject > Multiplication > Multiplying - one way

There's a limit to the number of multiplication facts that can be remembered so we need step-by-step methods for multiplication with larger numbers. There is more than one method including the one shown below and this other way of multiplying numbers.

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Multiplication - one way

3 x 13
o o o o o o o o o o o o o
o o o o o o o o o o o o o
o o o o o o o o o o o o o

We can split the 3 groups of 13 into:
3 groups of 3
and 3 groups of 10

Think of 13 in its expanded form. e.g. 3 + 10

o o o
o o o
o o o
o o o o o o o o o o
o o o o o o o o o o
o o o o o o o o o o

3 groups of 13

is the same as

3 groups of 3
plus
3 groups of 10

3 x 3 plus 3 x 10
9 + 30

3 x 13 = 39

animated example showing one method of multiplying two numbersWatch this animated example with explanations showing how to multiply 15 x 7 using the method above.

As shown in the following examples, we can write our multiplication calculation, by breaking the number to be multiplied into its expanded form.

13 x 3
1 3
x 3
9
1 3
x 3
9
0
1 3
x 3
9
+ 3 0
1 3
x 3
9
+ 3 0
3 9
Multiply the ones Put a zero in the ones' place as we're multiplying tens Add the products to get the answer
13 x 3 = 39

 

47 x 4
4 7
x 4
2 8
4 7
x 4
2 8
0
4 7
x 4
2 8
+ 1 6 0
4 7
x 4
2 8
+ 1 6 0
1 8 8
Multiply the ones Put a zero in the ones' place as we are multiplying tens Add the products to get the answer
47 x 4 = 188

 

318 x 6
3 1 8
x 6
4 8
3 1 8
x 6
4 8
0
3 1 8
x 6
4 8
+ 6 0
3 1 8
x 6
4 8
6 0
0 0
3 1 8
x 6
4 8
6 0
+ 1 8 0 0
1 9 0 8
Multiply the ones Put a zero in the ones place (as we are multiplying tens) and multiply the tens Put two zeros in the ones' and tens' places Multiply the hundreds and add to get the answer
318 x 6 = 1908

 


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Try the worksheets below for more practice with multiplying using the method shown above.

You'll find more free multiplication worksheets here.