Students do real world-math and make the connections between the real purpose for using rounding to estimate the costs of items. Students actually use real WalMart sales advertisements to learn how to round. They also use their skills of adding with regrouping as well as using rounding to estimate the cost and amount of money they will need to make purchases. Students compare the price of two items using greater than and less than. Then utilizing a different advertisement from a different store, students "go shopping" and round to estimate then check their estimates by adding the sum total of the cost of the items.