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Your Number Is...

Think of a number and follow the machine's instructions... I know what your number is! Can you explain how I know?

Diagonal Sums

In this 100 square, look at the green square which contains the numbers 2, 3, 12 and 13. What is the sum of the numbers that are diagonally opposite each other? What do you notice?

Finding 3D Stacks

Can you find a way of counting the spheres in these arrangements?

Price Match

Age 7 to 11
Challenge Level
Can you use the windows in the picture as a starting point?
What size window will you try next?  
How will you remember what you have found out so far?