Math Challenges: Puzzles, Tricks and Games - Tapa dura

A collection of over 70 brain-bending maths teasers, from grid and dot games to stretchy shapes and squiggly lines, mechanical and calculation puzzles to magic squares, and from vanishing tricks to amazing maps and mazes. The games and tricks featured include: fitting your entire head through a 3 x 5-inch postcard; calculating the duration of Big Ben's chimes; creating a deluxe Mobius strip; and escaping from rope handcuffs. There is a special chapter of mathematical puzzles and teasers created by Lewis Carroll, and 21 pages of answers are provided.