Archimedes thought hard for several days, but he still couldn't figure it out. One day, Archimedes went to take a bath. Because the water in the bathtub is too full, as soon as he enters the bathtub, the water overflows, and he feels that the water has a supporting effect on his body. He experienced buoyancy through the ups and downs of his body many times and realized that the more water his body displaced, the greater the buoyancy. He immediately thought that if the crown was mixed with silver, it would be bigger than gold with the same weight, and the buoyancy would be bigger than pure gold when it was put into water. Archimedes immediately jumped out of the bathtub, crossed the crowded street in ecstasy and went straight to the palace, shouting, "Found it! Found it! " Later, after Archimedes' strict inspection, it was proved that the crown was indeed mixed with silver, and the craftsman was also punished by the king.