1. Press the foil square flat on the desk. Use the ruler to measure one edge of the square. Then measure the other edge next to it. Multiply the two measurements to calculate the area of the foil. Record the area.
2. Fill the mixing bowl three-quarters full with water. Lay the foil in the water so it floats.
3. One by one, gently drop pennies into the center of the foil. Count how many pennies you can add before the foil sinks. Record this number.
4. Remove the pennies from the water, then lift out the foil and place it on a paper towel. Carefully press it flat.
5. Take each corner of the foil and fold it into the center to make a smaller square. Then repeat steps 1 through 4.
6. Fold the foil again to make an even smaller square. Then repeat steps 1 through 4.