We have been reading "Archimedes and the Door of Science". It is great because it tells a story then tells you how to do an experiment that goes with the story. We read about Archimedes running around naked shouting "Eureka" when he discovered how to prove the kings crown wasn't made of solid gold. Then we did some experiments with density, specific gravity, and buoyancy. We are supposed to be finishing up with this component this week, but we are having so much fun with it we might have to extend it a little.