1. Fill a 1-liter plastic bottle with water. This amount represents all of Earth’s water. 2. Pour 97.5 percent, or 975 milliliters, of the water into a large bowl. This amount represents Earth’s salt water. 3. Label cups Ice, Groundwater, and Lakes and Rivers. 4. Using the figure below, calculate how much of the remaining 25 milliliters should be poured into each cup.