 This is a mathematical snack from the Association of Teachers of Mathematics. Hello! This is a domino problem. I'm just going to work with a 4-4 set and I've arranged them so you can see that we probably have got all the dominoes in a 4-4 set. Yep, that looks alright. That's looking good. And last of all the blank blank. The challenge is this. I want you to split them into five groups with three in each group. So one, two, three, one, two, three, one, two, three, one, two, three, one, two, three. So in this group we're now going to count the spots in each of the groups. So in this group here we've got four eight twelve, fifteen spots. In this group we've got nine spots. In this group we've got twelve spots. In this group oh we've only got three spots. And lastly in this group well over nine, twenty-one I think. I think the twenty-one spots yes there are. I'm not going to tell you what that same number is because that's one of the parts, that's one part of the problem. When you've done that see if you can split them into three groups of five. And this time again we're going to try to put them so that each group has the same number of spots but it will be a different number of spots to the first problem.