What happens when children pour water through a funnel? They begin to understand science and math concepts such as flow, force, gravity, and volume. What happens when children mold sand to create a tunnel? They develop skills in areas such as problem solving and predicting. They also gain knowledge about absorption and the properties of sand and water, and what happens when they are mixed together. Sand and water encourage children to use everything from science skills to creative-thinking skills. But most of all they are just plain fun. This paper offers suggestions for sand and water activities that invite children to expand their thinking.