Sir Cumference and the Sword in the Cone

Subtitled “A Math Adventure,” this picture book is more accurately a math-oriented mystery. The story is set in a medieval castle-none other than King Arthur’s-and employs a cast of arithmetically-minded royals: Sir Cumference, Lady Di of Ameter, son Radius, and Radius’ best friend, Vertex. The two young knights are quickly embroiled in a puzzling challenge set forth by King Arthur in order to choose an heir. Five knights are competing for the honor, and Vertex is one of them. Soon Radius and he are working through the puzzle of how to locate where the king has hidden his sword, Edgecalibur, using only the clues given on a mysteriously-coded parchment. Much questing and questioning ensues, along with a few geometry lessons, until Edgecalibur and a new heir to the throne is discovered. Geehan’s lively full-color paintings evoke the spirit and style of medieval life well; even geometrical principles are explained in diagrams that reflect the art of the Middle Ages. Although sometimes the ‘math problem’ aspect of the book overshadows the storyline, teachers, parents and readers will enjoy the witty puns sprinkled throughout…and find that learning math can be fun after all.