I know this activity is nothing new, but after playing store with my young boys today, I was amazed at how many math concepts can come from such a simple activity.
"Since money is based on units of ten, children who understand and can use money will have a much easier time learning other concepts, such as decimals and percents. If you start your child playing store when they are pre-school age, you can continue all the way to algebra age by bringing different real-life aspects to the store such as sales and sales tax."
-Math On The Level, Math Adventures
We set up play food on Quentin's old Diego table. James was the storekeeper and he put prices on each of the items, which we had written on little squares of card-stock. Katie and I took turns being the shoppers. We talked to the storekeeper, asking him questions about his products and we got coupons from him. Then we went across the living room and Quentin played the checkout person. I took the price tags out of the card and lined them up on a white lunch-sized bag. I helped Quentin add these prices up since he is just getting to adding double-digit numerals. When Quentin had difficulty, I asked James to help out. We even had coupons for so much off, and I helped them subtract this. We even had a 10 percent off coupon, which introduced James to percentages. Katie and I would give Quentin a little more more money than our total, so he would have to give us change, which is once again some subtraction. We all had a wonderful time, and the boys just didn't want to stop! I can see that some of this at least will carry over to playtime on their own.