A brilliantly original tour of numbers, and what makes them special. Did you know there are 17 possible types of symmetric wallpaper pattern? Do you know what 'casting out the nines' is? Or why 88 is the fourth 'untouchable' number? Or how 7 is used to test for the onset of dementia? Number fanatic Derrick Niederman has a mission to bring numbers to life. He explores the unique properties of the most exciting numbers from 1 to 200, wherever they may crop up: from mathematics to sport, from history to the natural world, from language to pop culture. Packed with illustrations, amusing facts, puzzles, brainteasers and anecdotes, this is an enthralling and thought-provoking numerical voyage through the history of mathematics, investigating problems of logic, geometry and arithmetic along the way. 'A hugely entertaining pick-and-mix of history, culture and mathematical puzzles. If you aren't a number freak already, you soon will be once you start reading this.' - BBC Focus AUTHOR: Derrick Niederman is a mathematician turned investment writer. He is the author of several books on numbers and finance, including What the Numbers Say and The Inner Game of Investing. He has written a series of puzzle books and is regular contributor of crossword puzzles to the New York Times.