Cindy Neuschwander

Sir Cumference and the Dragon of Pi teaches a mathematical constant through a joke that runs the length of the book: the knight's son Radius has to work out the ratio of a circle's circumference to its diameter in order to mix an antidote and turn his father back from a dragon. Cindy Neuschwander wrote it and Wayne Geehan illustrated it, and the pair made a dozen or so of these together for Charlesbridge, on area, angles, geometry and place value. Neuschwander taught elementary and middle school for many years and wrote the books out of that classroom experience, aiming them at children who meet the idea in a story before they meet it as a definition.