Olivastro's combination of history and puzzles-to-solve may intimidate or simply put off some readers who are strictly of the "let's play" school. Others will be enthralled to learn of the antiquity of some of today's still-popular numeric puzzles. Along the way, the author delivers some fascinating information, such as the origin of the word stockholder and of a magic square devised by Benjamin Franklin. Here are some great ideas for enlivening a math classroom or blending math with history or social studies. Denise Perry Donavin