Sir Cumference and the Dragon of Pi

Sir Cumference, Lady Di of Ameter, and Radius are back in their second Math Adventure! This time, a potion has changed Sir Cumference into a fire-breathing dragon. Can Radius change him back? Join Radius on his quest through the castle to solve a riddle that will reveal the cure. It lies in discovering the magic number that is the same for all circles. This magic number, pi, will restore Sir Cumference to his former shape. Written by Cindy Neuschwander, Illustrated by Wayne Geehan, Paperback, Ages 8-12