Or search by topic
Here are nine triangles. Each one has three numbers on it.
Your challenge is to arrange these triangles to make one big triangle, so the numbers that touch add up to 10.
Once you've finished making the big triangle, think about these questions:
How did you get started?
What did you do next?
You can print out the sheet at the top of this page and cut the triangles out, then try arranging them.
If you prefer, you can also use a printable version of the triangles with numbers represented on tens frames.
Alternatively, you might like to use this interactivity, which allows you to drag each triangle onto the large triangle.
What is the greatest number of squares you can make by overlapping three squares?
Find all the numbers that can be made by adding the dots on two dice.
Andrew decorated 20 biscuits to take to a party. He lined them up and put icing on every second biscuit and different decorations on other biscuits. How many biscuits weren't decorated?