Follow the adventures of Sir Cumference, Lady Di of Ameter, Radius, and their friends as they are confronted with riddles they must solve. Mathematical concepts, angles, the number Pi, dimensional shapes, and degrees all find there way into with stories with fun word-play and puns and problem-solving that make new terms easy to remember. New mathematical concepts are introduced with each story in these 7 books. 

The books in this set include: 

Sir Cumference and the First Round Table - When King Arthur's knights get together, they sit at such a long table that everyone has to shout to be heard. Can Sir Cumference and Lady Di Ameter "measure up" to the challenge of building a better table?

Sir Cumference and the Dragon of Pi - Sir Cumference has been changed into a fire-breathing dragon. Can Radius solve the riddle that will reveal the cure? It lies in discovering the magic number that is the same for all circles.

Sir Cumference and the Great Knight of Angleland - Adventure by degrees. When Radius goes on a heroic quest with only a family medallion for luck, he must face the mysterious castle with the maze of many angles. Which way will he go? Join Radius on the adventure with the medallion at the back of the book.

Sir Cumference and the Sword in the Cone - Join Sir Cumference, Lady Di of Ameter, and their son, Radius, in this new adventure where they race to help Vertex find the sword and discover the secrets of cubes, pyramids, cylinders, and cones.

Sir Cumference and the Isle of Immeter -  This clever math adventure introduces readers to the concepts of area and perimeters. 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. 

Sir Cumference and All the King's Tens - Sir Cumference and Lady Di are planning a surprise party for King Arthur, but their plans are turning into a royal mess. Soon the tower to the moat is full of quests. How will they all be fed? The knight and lady race to count tens, hundreds, and even thousands of partygoers in this introduction to place value.

 Sir Cumference and the Viking's Map - Xaxon Yellowbearyd was the fiercest Viking warrior of his time. Now a map to his hidden treasures lies in the hands of Raius and Per. Together they must decode the strange numbered grid on the map—and figure out the secret of the Viking's X and Y axes.

Books are paperback, 32 pages. Recommended for ages 8-12.