To help you understand the algorithm, the video shows a simple two-digit by two-digit multiplication. You can see that the first and last digits are essentially the result of one multiplication.

This Maths article explains both the mental method and written method for multiplying a 2-digit number by a 1-digit number.

Using your times tables knowledge for small single-digit multiplication equations is great. When you are asked to multiply any two, three or four-digit number by multiples of ten, or any two-digit ...