There's a limit to the number of multiplication facts that can be remembered so we need stepbystep methods for multiplication with larger numbers. There is more than one method including the one shown below and this other way of multiplying numbers.
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: 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 
3 x 3 plus 3 x 10 3 x 13 = 39 
Click the arrows in the the animated example below to see the steps and explanations for multiplying 15 x 7.
As shown in the animated examples above and in the following examples, we can write our multiplication calculation, by breaking the number to be multiplied into its expanded form.
13 x 3  





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  





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  






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 
Try the worksheets below for more practice with multiplying using the method shown above.
You'll find more free multiplication worksheets here.