Monster and I worked out of the Magic School Bus Science kits we get each month. Today, we talked about water. The first project out of this lesson was a simple one. Does it sink? Does it float? We talked about how items that float are lighter than water, while items that sink are heavier than water.
He learned that most plastic is lighter while metal is heavier. He actually really enjoyed this one and even played with it for awhile after the lesson was over.
(I wrote the name of the item and the material while he checked off if it would sink or float.)