Working systematically
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problemMove from the START to the FINISH by moving across or down to the next square. Can you find a route to make these totals? - 
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problemTetrahedra tester
An irregular tetrahedron is composed of four different triangles. Can such a tetrahedron be constructed where the side lengths are 4, 5, 6, 7, 8 and 9 units of length?
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problemPainted cube
Imagine a large cube made from small red cubes being dropped into a pot of yellow paint. How many of the small cubes will have yellow paint on their faces?
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problemPaw prints
A dog is looking for a good place to bury his bone. Can you work out where he started and ended in each case? What possible routes could he have taken? - 
problemPeaches today, peaches tomorrow...
A monkey with peaches, keeps a fraction of them each day, gives the rest away, and then eats one. How long can his peaches last?
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problemTilted squares
It's easy to work out the areas of most squares that we meet, but what if they were tilted?
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problemSquirty
Using a ruler, pencil and compasses only, it is possible to construct a square inside any triangle so that all four vertices touch the sides of the triangle.
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problemBreak it up!
In how many different ways can you break up a stick of seven interlocking cubes? Now try with a stick of eight cubes and a stick of six cubes. What do you notice?
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problemAll seated
Look carefully at the numbers. What do you notice? Can you make another square using the numbers 1 to 16, that displays the same properties?