Sir Cumference and the Roundabout Battle: A Math Adventure

Gr 2–5—This latest series installment uses stories involving a knight named Sir Cumference as jumping-off points to explore mathematical concepts tackles rounding. Edmund Rounds and his son, Rounds 2, are responsible for keeping an inventory of items at Sir Cumference's castle. When Rounds 2 hands over his latest counts for inspection, Edmund notices that the number of bread loaves and butter pots has not been totaled. Rounds 2 admits that adding is the difficult part. As they total the items together, he finds that it is much easier to calculate numbers in groups of 10 (10, 20, 30, etc.). His father tells him that for some items, such as the number of bees in the hives, it's acceptable to come up with an approximate number. To thank his father for his assistance, Rounds 2 sets off to count the bedding of some travelers passing by but discovers that the men are enemies intent on attacking the castle. As Sir Cumference prepares for battle, he asks Rounds 2 to retrieve the bow and arrow counts. While these items have been counted, they have not yet been totaled, and Rounds 2 is left to complete the calculations himself. By rounding up or down to the nearest 10, Rounds quickly completes the task in what soon becomes known around the castle as the Rounds 2 Method.