What makes this book of maths puzzles so mesmerising? Some tricky ones use just addition, subtraction, multiplication and division. What must you do to "win"? Test your aptitude for mathematics, for example, by finding the secret to numbers or figures in a sequence. Other puzzles challenge you to use traditional geometric figures that you must arrange into equal parts: use your visual intuition and mental flexibility to sort them. Other challenges are games using pentominoes (five-sided dominoes, which make up into a jigsaw): it all adds up to more than 90 great ways to test your talent at manipulating numbers.