Go fill a glass of water and float some ice cubes in it. Mark the water level on the side of the glass. Watch the water level remain constant as the ice melts.

Go fill a glass of water and float some ice cubes in it. Mark the water level on the side of the glass. Watch the water level remain constant as the ice melts. Another experiment: fill a glass with water and ice so the ice isn't floating. Then watch the water level increase.