Sir Cumference and the Isle of Immeter

When young Per visits her uncle Sir Cumference and his family, she learns how to play the game, "Inners and Edges." After she finds a clue linking the game to the mysterious castle on the island of Immeter, she must figure out how to find the perimeter and area of a circle to unlock the island's secret.

In this wonderfully illustrated series, go on math adventures with Sir Cumference, Lady Di of Ameter, and their son Radius. Each book presents a mathematical concept in such a way that it allows students to fully comprehend "how" and "why" the characters solve their unique problems.