Assisted by his knight, Sir Cumference, and using ideas offered by his wife and son, King Arthur finds the perfect shape for his table.

To earn his knighthood, Radius must find and rescue a missing king. His father, Sir Cumferance, and his mother, Lady Di of Ameter, give him a circular medallion (a protractor) that he uses to find his way through a maze of many angles.

Discusses young Per taking a mathmatical adventure.

"Xaxon Yellowbearyd was the fiercest Viking warrior of his time. Now a map to his hidden treasure lies in the hands of Radius and Per. Together the cousins must decode the strange numbered grid on the map--and figure out the secret of the Viking's X and Y axes. As bandits pursue them, Radius and Per track down clues and use coordinate geometry in their quest for "treasure of the greatest measure"."--Dust jacket flap.

"When Steward Edmund Rounds and Sir Cumference notice that there are strangers camped nearby, Rounds II decides to investigate despite being involved with the task of learning how to make accurate counts of the castle's stores of food, supplies, and weaponry. When he reports back that an enemy is lying in wait, everyone moves quickly to defend the castle. But wait! Will Rounds II be able to figure out how many bows and arrows they have to create an...