Lesson 21

The purpose of this warm-up is to introduce students to the context of food waste, which will be useful when students keep a journal of food waste in a later activity. While students may notice and wonder many things about this illustration, what students consider to be food waste in their neighborhood or community is the important discussion point.

• Groups of 2
• Display the image.
• “What do you notice? What do you wonder?”
• 1 minute: quiet think time

• “Discuss your thinking with your partner.”
• 1 minute: partner discussion
• Share and record responses.

• "What kinds of things do you think we throw out when we cook or eat at home or outside?” (food scraps, leftover food, spoiled ingredients or food, packaging for food)
• “What are some reasons we throw out food?” (It’s spoiled. It smells or looks bad. We don't want it anymore. It’s too old. It fell on the floor.)
• Record responses and keep it displayed.

The purpose of this activity is to make reasoned estimates about the weight of food waste produced by individuals, families, and the school community each week and each month. Answers will vary widely based on the size of families, the class, and the school. Students use multiplication and division appropriately in their estimates.

• Groups of 2
• "The average person in the United States throws out about 219 pounds of trash related to food waste each year. We are going to estimate the amount of food waste we produce based on this data."

• 5 minutes: independent work time
• 5 minutes: partner discussion
• Monitor for students who:
  • use their result for the month to get their result for the week
  • divide 219 by 52 to get the weekly result
  • make reasoned estimates

• Invite students to share their strategies for determining how much food waste they produce per week.
• “Were you surprised at the estimate of how much food waste everyone in your school produces in a year?”

The purpose of this activity is to introduce the food journal that students will use to track the food waste they or their families produce for a week. In this activity students practice filling out the journal and estimate the weight of what they throw out. To help students develop a sense for the weight of the food waste, consider bringing in a few common food items or images and display their weights in ounces. A few examples are provided below.

Banana: 4 ounces
Cucumber: 7 ounces
Chicken thigh: 2–3 ounces
Small lemon: 2–3 ounces
Carrot: 2 ounces
Medium apple: 6–7 ounces

• Groups of 2
• “Think about one thing related to the food that you threw out today. Share with your partner. Why did you throw it out? How much do you think it weighed?”
• 1 minute: partner discussion
• Display food journal.
• Record responses on the food journal.
• “Try your best to think about all the food waste you produced today to complete the table.”

• 5 minutes: independent work time
• 5 minutes: partner work time
• Monitor for students who:
  • divide the total number of ounces of food waste by 16 to determine the pounds of food waste
  • multiply appropriately to compare the estimated pounds of food waste from the previous activity

• Invite a few students to share how they found the total pounds of food waste produced.
• Give each student a food waste journal.
• “For the next week, you will keep track of the food waste you produced. Record what you throw out, why you throw it out, and the estimated weight in ounces.”
• “Scientists collect this kind of information for cities and countries all over the world. Why is this information helpful to them?” (to see why people are throwing things out and see how to reduce it, to see how much food waste is going to landfills, to learn what is in food waste and see how that affects the environment)

The purpose of this activity is for students to analyze their completed food waste journals. Students begin the activity by sharing their food journal with a partner and discuss a few things they notice. Then they use the data from the journal and their experience with multiplying and dividing large numbers in this unit to estimate how much food waste they might produce in a month and in a year. They compare those results to the national average and discuss some possible reasons for the difference.

• Groups of 2
• “Share your food waste journal with a partner. As you look over your journals, what do you notice?”
• “What is the same? What is different?”

• 10 minutes: independent work time
• 2 minutes: partner discussion

• See lesson synthesis