Learning to add and subtract is fun when children use the calculator cash register! selling products in their "store" of choice, ringing up purchases and making change are all part of the game. Choose a new business every day and help your child decide on the products he or she wants to stock. How much should things cost? they can manage a grocery store, a shoe store or even a train station, issuing tickets and giving directions—all using the pretend play calculator cash register. As they play, younger children can be encouraged to Count while learning early addition and subtraction. Older children can build money math skills and practice early multiplication and division.