We filled our water tub with colored water, various sized pitchers, large containers and small, colored plastic animals. We just stood back and observed the children's play.
We wanted to promote children's curiosity, to experiment and ask questions (what causes what to happen?), to practice the skills of problem solving and cooperative play, to help grasp the "more vs. less" concept and number sense, and to lead to an understanding of volume and measurement.
Children learned that it takes a lot of small pitchers of water to fill a large container. Some pitchers hold "more or less" than others. We can sort the animals by color. We can fill a container faster if a friend helps.