It can be surprising which objects float and which don't. An apple floats, but a ball of aluminum foil does not. But if that same ball of foil is shaped into a boat, it floats! Why? And how is it possible that a huge ship made of steel floats? Answering these questions about density and flotation is David A. Adler's clear, concise text, paired with Anna Raff's delightful illustrations. Activities that demonstrate the properties of flotation are included.