This book has something for all ages.  I shared it with high school kids interested in mathematics, and they couldn't put the book down.  Then I showed it to mathematical researchers, and they loved sections too.  The book is composed of many short snippets to increase the reader's curiosity about mathematics.  The book is also loaded with puzzles.  I particularly liked "The Stained Glass Squares of Constantine."  Everyone I show it to seems to give a different answer.