It's your turn to make up the sums! How many ways can you make 100 just using the numbers shown on the page, which are all multiples of 10. Sammy Snail has two extra rules for this investigation: 1. You must use 3 of the numbers. 2. But the numbers can be used more than once. So, using Sammy Snail's rules you could have 10 = 20 + 70 = 100 or 10 + 10 = 80 = 100 At first glance you might think that there are a lot of possible answers, but there are not as many as you might think, because of the restriction on using 3 numbers. The investigation could be developed further: What would happen if I used 4 numbers?....or any number of numbers? Addition: How many ways of making 100?