Understanding the process of multiplication can be quite a tricky challenge for some children. An introduction to this number operation will usually show that multiplication is, in fact, repeated addition. For example, the calculation of 3 x 4 is the same as 3 + 3 + 3 + 3 or 4 + 4 + 4. They are then encouraged to use mental methods to solve multiplication problems by using the number facts they have learned, for example if 3 + 3 + 3 = 9 then 3 x 3 = 9. This is closely related to the mental methods children learn to solve division problems.