The calcium in bones helps to make them very strong.
To explain the strength of bones, take a sheet of paper and roll it into a tube making sure that the top and bottom overlap in the tube. Tape it together. Stand the tube on it’s side and place a book on top of it. The paper tube is strong enough to hold a book. Continue adding more books. Record your observations.
Explanation: The longest and strongest of the long bone is the thigh bone, or femur. It supports the weight of your body when you walk. Did you know the thigh bone is hollow like a cylinder.
The hollow, paper tube acts like the femur. It will support the weight of a stack of books very easily, just as our femur supports our body weight.