Tips and hints on how to use mental methods to double and halve larger numbers, including 3-digit numbers.

Using tables knowledge and doubling to multiply by 12, 24, 18 etc.

Multiplying by 101 or 99 in your head. Sounds difficult, but you can do it by multiplying by 100 and then adjusting.

Multiply a decimal fraction by 10 or 100: remember to move the digits one place to the left or two places to the left.