“Sir Cumference and The Dragon of Pi” is a good math book for 9 to 12 year old’s by Cindy Neuschwander and illustrated by Wayne Geehan.

Sir Cumference had a pain in his stomach and it felt like he had a fire belly. His son, Radius goes out to get a cure. The doctor was out so he went and found a potion called Fire Belly. Radius thinks that this will help his father but his father turned into a huge dragon. Radius finds a potion but he needs an exact measurement or his father, will be killed by the knights. He finds his cousin, who is a chef who is making pie and he finds out the the circumference of a circle after measuring different circles with the diameter. He fell asleep with the potion and when he woke up he ran out and saved his father. This book was really great as it taught kids about Pi and Circumferences in a fun tale.