Knowing your multiplication facts is very useful, but what happens when the numbers you are multiplying are greater than those in your multiplication tables? You will need to calculate using a column ...

The array can be shown as 5 groups of 3 showing that 5 x 3 = 15. Or it could be shown as 3 groups of 5 showing that 3 x 5 = 15. This demonstrates that multiplication is commutative. Image caption, ...