Methods for doubling and halving

Doubling is the same as multiplying by 2, so any method that works for multiplying by 2 also works for doubling. The same is true for halving and dividing by 2.

1. Use objects or fingers to help.

2. Use knowledge of 2 times table

3. Write down the number. Split it into tens and ones. Double or halve each part then add the answers back together.

Eg. doubling

Remember to separate the tens and ones to 30 and 4, not 3 and 4!

This method can also be used for halving.

If it is difficult to halve the tens, separate the tens into a 10 and the rest of the tens.

eg. halving