MATHEMAGIC!

Stun friends and family members by guessing secret numbers and doing painless long division. Dice and card tricks and finger multiplication are among the fascinating tricks potential mathemagicians will learn to perform. But Colgan goes beyond the ordinary by giving an in-depth, easily understandable explanation of the math behind each trick, as well as any history that might be applicable, too. Not only will readers learn how to multiply large numbers in their heads, they will learn why this trick works and that the early Egyptians used the very same method. Prime numbers, Napier’s bones, division dowels, the binary number system and factoring are just a few areas they will explore. Kids won’t stop with just learning the tricks—the emphasis is on performing them, and the author does a great job of giving tips for a magical performance that is not only believable but entertaining as well. Backmatter includes a glossary, but the language used in the definitions is more advanced than that used in the text, and the terms used within the entries are not always themselves defined. Kurisu’s illustrations emphasize the performance side of mathemagic, showing potential performers how to successfully set up or follow through with specific tricks. Colgan makes math cool, and that speaks for itself. (Nonfiction. 10-14)