How many different triangles can you draw which each have one dot in the middle?

This is a game for two players. Can you find out how to be the first to get to 12 o'clock?

The computer has made a rectangle and will tell you the number of spots it uses in total. Can you find out where the rectangle is?

In these addition games, you'll need to think strategically to get closest to the target.

Four bags contain a large number of 1s, 3s, 5s and 7s. Can you pick any ten numbers from the bags so that their total is 37?

How many possible symmetrical necklaces can you find? How do you know you've found them all?