For bright and lively 8-12 year olds, and adults, for that matter. Designed to stimulate kids and introduce them to concepts they are unlikely to meet yet in traditional schoolrooms.This is the third book in the Number Magic series by Grandpa Mike KH, written to stimulate a bright and lively 8-year-old granddaughter. It should appeal to inquisitive and intelligent 8-12-year-olds who still lack the background skills needed to make the most of Martin Gardner, Simon Singh. Marcus du Sautoy or Alex Bellos, and also to a lot of adults.