The fourth graders experimented using spring scales to measure the amount of force needed to move a stack of books.  Then, they placed a jar lid and marbles under the stack of books.  Pulling the books again with the spring scale, they measured the amount of force now needed.  This creation of a simple machine demonstrated to students how machines can make work easier.

Fourth graders experimented with an egg and several shock absorbing materials to scientifically determine how best to protect an egg from a 2 meter drop.  We had fun (not so much the eggs) and learned a lot.