problem Out of sync Age 11 to 14 Challenge level Albert Einstein could see two clocks which were out of sync. For what fraction of the day did they show the same time?
problem Sticks and triangles Age 7 to 11 Challenge level Using different numbers of sticks, how many different triangles are you able to make? Can you make any rules about the numbers of sticks that make the most triangles?
problem Impossible triangles? Age 16 to 18 Challenge level Which of these triangular jigsaws are impossible to finish?
problem It's a fence! Age 5 to 11 Challenge level In this challenge, you will work in a group to investigate circular fences enclosing trees that are planted in square or triangular arrangements.
problem Newspaper sheets Age 14 to 16 Challenge level From only the page numbers on one sheet of newspaper, can you work out how many sheets there are altogether?
problem Stairs Age 5 to 11 Challenge level This challenge is to design different step arrangements, which must go along a distance of 6 on the steps and must end up at 6 high.
problem Calendar capers Age 11 to 14 Challenge level Choose any three by three square of dates on a calendar page...
problem Difference Age 7 to 11 Challenge level Place the numbers 1 to 10 in the circles so that each number is the difference between the two numbers just below it.
problem Top-heavy pyramids Age 11 to 14 Challenge level Use the numbers in the box below to make the base of a top-heavy pyramid whose top number is 200.
problem Amazing alphabet maze Age 5 to 7 Challenge level Can you go from A to Z right through the alphabet in the hexagonal maze?