Challenge your learners to cross a piranha-infested river. Actually, it's just the gym floor, and they are trying to get from point A to point B, but the story makes it a more interesting challenge. Each group has two mats a given distance apart. They will start on one mat and use stepping stones (wooden blocks) to get across to the other mat. Each group gets a certain amount of blocks and they must use teamwork and strategy to get across. Of course, the distance between mats should be adjusted according to the age level of your class.