1. Use to choose two items to buy and place them in the cart. 2. Choose the coins you would need to buy your items with the tool. 3. Tap to write your number sentence. * Challenge: Think of other coin combinations you could use to buy your items. Use to write more number sentences. Tap to write your shopping story as a math problem for a friend. 4. Tap to explain your mathematical thinking. 6. Tap the to save your work.