Mathematical brainteasers increase in complexity as a reader - or a teacher leading a class - advances through the 35-plus challenges in this book. Topics include prime numbers, square numbers, tangrams, the four-color map problem, Jordan curves, the topology of knots, Alquerque, Sudoku, Egyptian multiplication, Plato's solids, Euler's Konigsberg bridge problem, Pascal's probability triangle, and Fibonacci's rabbits. Grades 5-8. Index. Bibliography. Glossary. Answer key. Illustrated. Good Year Books. 136 pages.