Being collaborative

Each clue in this Sudoku is the product of the two numbers in adjacent cells.

Powers of numbers behave in surprising ways. Take a look at some of these and try to explain why they are true.

How will you complete these interactive Venn diagrams?

On the graph there are 28 marked points. These points all mark the vertices (corners) of eight hidden squares. Can you find the eight hidden squares?

Can you put the numbers 1-5 in the V shape so that both 'arms' have the same total?

If you are given the mean, median and mode of five positive whole numbers, can you find the numbers?

Try this version of Snap with a friend - do you know the order of the days of the week?

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

Here's a chance to work with large numbers...

This problem offers you two ways to test reactions - use them to investigate your ideas about speeds of reaction.