Choose any three-digit number whose first digit differs from the third by at least two. Write them in reverse order and subtract the smaller of the two numbers obtained from the larger one. Add the same number written upside down to the resulting number. Did you get a 1089? Then you calculated correctly. David Acheson's sweet and witty book presents a remarkably entertaining survey of the mathematical landscape. Individual topics include well-known and lesser-known fascinating puzzles (King's Bridges, the orange-packing problem, Fermat's Big Theorem, the Indian rope trick, etc.) that extend into topology and physics. The author describes the most beautiful mathematical relationships, important historical connections, and also provides instructions on how to make mistakes correctly. The text is aptly illustrated by world cartoonists. In short, it is one of the most readable mathematical expositions of all time.