David A. Adler

When Grandpa's lucky hat goes missing during a college football game, detective Jeffrey Bones and his friend Sally help look for it.

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? Adler answers questions about density and flotation with clear, concise text, paired with Raff's illustrations. Activities demonstrating the properties of flotation are included.

"This introduction to mathematical estimating and rounding explains the difference between the two, their uses, and gives directions for estimating and rounding."--

"Two children learn about four different states of matter (solid, liquid, gas, and plasma) and what happens when matter changes form."--