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Make a cube out of straws and have a go at this practical challenge.


Reasoning about the number of matches needed to build squares that share their sides.

Little Boxes

How many different cuboids can you make when you use four CDs or DVDs? How about using five, then six?

Clocking Off

Age 7 to 16
Challenge Level

Four clocks in a row

These clocks can be found in the Arts Centre at the University of Warwick.

What was the time when I took this picture?

If I hid one of the clocks would you still be able to tell the time?
Would it make a difference which clock I covered?
Would there be periods of the day when I could not work out the time if there were only three clocks and what would those periods be for different combinations of three clocks?

Below are some pictures of just two of the clocks. What periods during the day would you not be sure of the time in each case?
Two clocks
View of two clocks

View of two clocks