Lunch Trash Audit

Lesson Plan

Morgan Pestorius

Title or Topic of the Lesson: Lunch Trash Audit (adapted from Waste-Free Lunches: A Lesson in Environmental Stewardship by Amy Hemmert)

Grade Level: 3rd

Lesson Essential Question(s): How do our choices affect the environment?


Develop a model to describe the movement of matter among plants, animals, decomposers, and the environment. 5-LS2-1

CCSS.MATH.CONTENT.3.MD.A.2 Measure and estimate liquid volumes and masses of objects using standard units of grams (g), kilograms (kg), and liters (l). Add, subtract, multiply, or divide to solve one-step word problems involving masses or volumes that are given in the same units, e.g., by using drawings (such as a beaker with a measurement scale) to represent the problem.

|B| Responsible Local & Global Citizenship The rights, responsibilities, and actions associated with leadership and participation toward healthy and sustainable communities. Students will know and understand these rights and responsibilities and assume their roles of leadership and participation. The Cloud Institute

|E| Healthy Commons Healthy Commons are that upon which we all depend and for which we are all responsible (i.e., air, trust, biodiversity, climate regulation, our collective future, water, libraries, public health, heritage sites, top soil, etc.). Students will be able to recognize and value the vital importance of the Commons in our lives and for our future. They will assume the rights, responsibilities, and actions to care for the Commons. The Cloud Institute

Learning Objectives and Assessments:



Students will be able to sort waste from the lunchroom into 6 categories: non-recyclable trash, non-compostable food waste, compostable food waste, unopened food and drink, aluminum cans and bottles, and plastic bottles. The teacher will observe the students sorting the waste into buckets labeled with each category before weighing and recording the weight on their data chart.
Students will be able to record and analyze data from their trash audit. The teacher will facilitate a class discussion following the trash audit and listen to the student responses.


  • 1 large trash bag per grade (labeled with grade level)
  • 6 large buckets (each labeled with one of the waste categories from the Trash Audit Tally chart)
  • 1 tarp
  • scale
  • rubber gloves (1 set for each student)
  • Trash Audit Tally chart (1 for each student). Download here: trash-audit-tally-chart
  • clipboards (1 for each student)

Pre-lesson assignments and/or prior knowledge: Prior to teaching this lesson, make sure that the students are aware of the different types of trash. Review the difference between recyclable material, compostable material, and waste. Students should understand that when an item is put in the trash, it will be brought to a landfill or incinerated.

Lesson Beginning: Facilitate a class discussion about the waste produced in the lunch room. Ask students to make a prediction about how much waste they think that the school produces per day. Ask the students if they think students in different grades produce the same amount of trash or different amounts. Encourage students to explain their thinking during this discussion. Record the two predictions on the board for easy reference.

Instructional Plan:

  • Bring the labeled trash bags to the cafeteria. Put a small group of students in charge of monitoring the bags and instructing their classmates to throw their lunch trash in their grade’s garbage bag instead of in the trashcan. Allow the students to recycle if this is part of their normal routine.
    • TIP: If your school holds a lunch period where all of the students eat at one time, put a few students in charge of each bag. (3 students for the kindergarten bag, 3 for the 1st grade bag, etc.) If your school has multiple lunch periods, assign small groups to each lunch period so that your students are missing only a small amount of class time.
  • Once all of the trash has been collected, bring it outside or to the gym where there is room to work. Dump out the trash bag from one of the grades onto the tarp.
  • Model for the students how to weigh the empty buckets and record the weight on their Trash Audit Tally chart. Place the buckets along the edge of the tarp.
  • Distribute gloves to each student and instruct them to sort the trash by placing it in the appropriate bucket.
  • Once all of the waste has been sorted, the students should weigh the buckets and record the weight on their chart.
  • Empty the buckets by placing the contents into the appropriate containers (recycling bin, compost bin or trashcan).
  • Repeat the sorting of the waste and recording of data for each grade level’s bag.
  • After returning to the classroom, facilitate a discussion about the findings of this trash audit. Were the students predictions correct?
  • Discuss how the students can reduce the amount of trash they produce in the lunchroom everyday.
    • Extension Activity: Have the students design a PSA (poster, brochure, commercial) that makes recommendations for how the school can reduce lunch waste.
    • Extension Activity: Assign 2 students every week to be the class composters. These students will bring the organic waste from the lunchroom out to the compost bin.
    • Extension Activity: If you plan on implementing a waste free lunch program, perform one trash audit before the program begins, and one several weeks into the program. Compare your findings.

Differentiation: This lesson caters to many different learning styles and can be easily adapted for the students in your classroom. Kinesthetic learners will enjoy sorting the trash into categories, mathematical learners will thrive when weighing the trash and recording the data, and linguistic learners will show their understanding during the classroom discussions. Feel free to assign tasks to students based on their ability or to divide students into groups based on their learning style.


  1. Which grade do you think produces the most waste? Why?
  2. How much waste do you think our school produces on a given day?
  3. Where does trash go when we throw it away?
  4. Why is it important to reduce the amount of waste we create?
  5. What are some ways we can reduce the amount of waste we produce?

Classroom Management: Students can easily become distracted with lessons that take place outside of the classroom. It is important that before beginning this lesson, you review your expectations with your class. If a student is misbehaving during the lesson, I recommend that you give the student one warning before removing him or her from the lesson.

Transitions: When moving from your classroom to the lunchroom, remind your students to walk quietly in the hallway so that they do not disturb other classes. Before transitioning from one part of the lesson to another, I recommend telling the students what will come next so that they know what to be prepared for in the next setting.

Closure: Ask the students to think of one way that they can reduce waste in their own school lunch. Have the students write down this goal and tape it to their desk as a reminder.



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