What does the table data show about how common fresh water is compared to salt water?
- Fresh water is a tiny 3% compared to 97% salt water (correct answer)
- Fresh water is about half of Earth's water
- Fresh water is 97% and salt water is 3%
- Fresh water is the largest amount of Earth's water
Explanation: This question tests students' ability to use data to compare the amounts of salt water and fresh water on Earth (NGSS 5-ESS2-2). The table data shows fresh water is only 3% of Earth's total water, while salt water is 97%. This means fresh water is indeed 'tiny' compared to the vast amount of salt water in Earth's oceans. Despite water covering most of Earth's surface, the fresh water that humans and most life depends on represents just a small fraction of the total. Choice A is correct because it accurately describes fresh water as a 'tiny 3%' compared to the dominant '97% salt water.' This demonstrates understanding that students can read data and interpret what these percentages mean about relative abundance. Choice C is incorrect because it reverses the percentages, claiming fresh water is 97% and salt water is 3%. This misconception commonly occurs when students think about the importance of fresh water to life and assume it must be the larger amount, or when they misread the table by matching the wrong percentage to each water type. To help students: Use a 100-bead string with 97 blue beads (salt water) and only 3 white beads (fresh water) to show how 'tiny' the fresh water portion is. Create analogies: 'If Earth's water filled a bathtub, only 3 teaspoons would be fresh water.' Have students survey 100 drops of water, making 97 salty and 3 fresh, to experience the ratio. Emphasize reading tables carefully: finger-trace from 'fresh water' to its percentage. Watch for: students who reverse percentages, who confuse importance with abundance, or who don't understand that 'tiny' accurately describes 3% compared to 97%.