JESS' TOP TIP : ADDING NINE

Because I have trouble with my nines my maths teacher passed on this top tip.

What's a really simple way of adding 9 or 90?

For example: 78 + 9 =?
Easy - first you add 10 to make 88, and then take one away to make 87.

Adding ten, then taking one away is the same as adding nine - but it's much quicker!

For example: 86 + 90 =?
Easy again - first you add 100 to make 186, and then take ten away to make 176. Adding 100 then taking 10 away is the same as adding 90.