Use this slideshow as a lesson on money. Students can either have play money and try to make the prices shown, or partner students up and have one student be the customer and one student is the cashier. Have the customer pay the cashier NOT using exact change, and have the cashier use subtraction to figure out how much change the customer needs. Then, have the cashier give the change, and switch roles with each slide. Students LOVE this activity, and this creates very little prep for you!