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Domino Square

Use the 'double-3 down' dominoes to make a square so that each side has eight dots.

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4 Dom

Use these four dominoes to make a square that has the same number of dots on each side.

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Pair Sums

Five numbers added together in pairs produce: 0, 2, 4, 4, 6, 8, 9, 11, 13, 15 What are the five numbers?

A Mean Tetrahedron

Stage: 3 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

A tetrahedron has 4 vertices, 6 edges and 4 faces. Can you number them 1 to 14 in such a way that the number on each edge is the mean of the two numbers at the vertices joined by that edge and also the mean of the two numbers on the faces it separates?