Eating your Energy’s Worth

(Exploring energy consumption through food)

Overview:

In this lesson, students will use the “Energy Calculator” to explore the consumption of energy. This lesson takes a novel approach to introducing the concept of energy consumption by starting an activity where students make predictions about the energy content of “student-friendly” food energy units and exercise. In the second part of the lesson, students make and test predictions with regards to home appliances. Students devise ways to use the Energy Calculator to test their predictions and use everyday quantities like food units to begin to grasp the relative magnitudes of energy use by appliances and the equivalent amount of work in terms of human exercise and physical activity. One 50-minute long class period is recommended to complete this lesson.
This lesson can be implemented in a stand-alone fashion to address the basic premise of connecting food energy units to more conventional and less conceptually accessible physical science energy and power units like the joule and the watt or in conjunction with other E21 lessons "Walk a Mile for a Burger?" and "Electricity Unplugged" which are located at http://www.pspb.org/e21.

Content Objectives
Students will know that

1. There are different forms and sources of energy.
2. People get chemical energy from the food they eat.
3. Foods contain different amounts of energy.
4. People use electrical energy to power appliances.
5. Different physical activities burn food energy at different rates and different appliances use electrical energy at different rates.

Process Objectives
Students will be able to

1. Compare activities by how fast they burn calories.
2. Compare appliance use by the rate they use energy.
3. Calculate the amount of electrical energy used in a week in food units
4. Develop ways to reduce energy use.

Assessment Strategies

1.Evaluation of completed student handbook.
2.Participation in classroom discussion on energy conservation.

Materials

Per group:
• Computer with access to Microsoft Excel
• Excel file, “Energy Calculator,” that accompanies this lesson

Per student:
• Student handout

Procedures

Parts 1 & 2: (1, 50 min Class Period)
1. This activity incorporates small group discussions. At the start of the lesson, frame the activity by introducing the first section that involves predicting the amount of energy in certain types of food.
2. As groups progress through the lesson, be sure to monitor student progress and facilitate discussions.
3. During part I, students will be using the blue section of the Energy Calculator. During part II, students will be using the yellow section of the Energy Calculator.
4. At the end of the activity, you can have the class discuss their explanations and predictions in a large group setting.