Sir Cumference and the Viking’s Map (Charlesbridge Math Adventures)
Xaxon Yellowbearyd was the fiercest Viking warrior of his time. Now a map to his hidden treasure lies in Radius's and Per's hands. 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 bungling bandits pursue them, Radius and Per use coordinate geometry in their quest for "treasure of the greatest measure". More »