Scavenger Shop
This classic game usually involves kids hunting for items in the house or the neighborhood, but they also can do it in the market. To avoid having to go on a hunt yourself, limit the scavenger game to the aisle or department you're in, or ask your child to search only the shelves right next to your cart. When you turn the corner into the cereal aisle, challenge your child to find Dad's favorite brand, then maybe two cereals with pictures of raisins on the box. Each aisle is a new hunting ground.
Questions to ask: How many sizes of canned tomatoes are there? Can you find five colors of yogurt containers?

Weight Training
The scale in the produce department may be the best tool in the store for learning and fun. Let your child help you weigh items, especially when you're buying various types of produce. My youngest used to enjoy simply watching the arm on the scale move with each added piece. Toddlers and preschoolers can count the items as you place them on the scale and note how much they weigh.
Questions to ask: Why do three apples weigh less than two cantaloupes? Which will weigh more, four apples or four oranges? "The oranges are bigger but they aren't as heavy," explained my neighbor's daughter during a shopping trip.