Medieval math favorites Sir Cumference and Lady Di of Ameter learn a method to calculate volume in this adventure story introduction to a math curriculum staple. While on horseback, Sir Cumference hears news about an impending snow siege from a young countryman named Volomo Longitudo Latitudo Altitudo. Volomo invites Sir Cumference in and shows him a nifty method for storing grains so that the harvest is easily countable and stackable. At the castle, Sir Cumference and Lady Di open their doors for people to seek shelter during the blizzard. But when they run out of food, Sir Cumference and Lady Di must use Volomo's method to measure how much grain they need to feed everyone. This thirteenth book in the Sir Cumference series teaches solid math skills with clever problem-solving.