Abstract :
Open one of the 179 "drawers" in Professor Stewart\´s cabinet, and you might find just a one-liner (Why did the chicken cross the Mobius band?") or a seven-page essay on Ferman\´s last theorem. It features a variety of knots, magic hexagons, square wheels, and topology tricks in which you pretend to slice off your finger. Answers are found at the back of the book and many have URLs for further information. The puzzles require at most a bit of algebra and many should be within the grasp of an intelligent 11-year-old.
