It's useful to be able count forwards and backwards in 5s. It's much quicker than counting in 1s. There is a pattern when counting in 5s that can be easily seen on a 100 square or number line ...

Counting in fives When you count in fives you could use a number line such as this. You could also look at a hundred square. Do you see a pattern? Each multiple of 5 in the grid has a difference of 5.