After peeling, measure the mass of the peeled potato and the skins. Draw a pie graph to show how much of the mass of the original potato has been lost in peeling. Use this to illustrate how food processing can rob foods of their essential nutrients. If the potato has been peeled, the peels create waste. If the peels have to be removed, they should be composted to produce compost for a garden or a flower bed.
Students draw inferences from the implications of what they learned.
By relating the activity to preparing and eating foods, and to personal hygeine, students make connections between the activity and things of importance in their lives. Ask students to think about how a cell is like a city. Have them discuss this with partners, then brainstorm as a whole class. They can share in small groups and participate in a large group discussion. In small groups, students are asked to think about all the ways that cells and cities are different.