- a penny, and other coins
- an eyedropper
- water, or other liquids
- Set a dry penny on a table or counter top.
- Use the eyedropper to slowly place one drop of water at a time onto the penny. Keep count of how many drops you add.
- Keep adding drops until the water spills over the edge of the penny.
- What's the greatest number of drops you can add without spilling? What happens if you try milk, or vegetable oil, instead of water?
Which coin holds the most water drops?