Throughout the activities in this investigation, students may have wondered how a boat made out of steel, which is more dense than water, can float. This activity addresses that question. Students will see that changing the shape of an object, like a clay ball, that is more dense than water, can affect whether the object will sink or float. The density of the clay used in this activity does not change, but the volume of the object made from the clay increases. This increase in volume decreases the overall density of the object, making it float.