Join Sir Cumference for wordplay, puns, and problem solving in this entertaining, medieval math adventure story about radius and the number Pi. This time the math adventure is centered around a potion that changes 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. The second in Sir Cumference series, Sir Cumference and the Dragon of Pi makes math fun and accessible for everyone.