Beacon Lesson Plan Library

Saving Money Through Mathematics

Kenneth Blackman
Santa Rosa District Schools


The students compare the cost of energy use for a variety of sources of light. A variety of graphs will be used to make the comparison.


The student knows the appropriate operations to solve real-world problems involving integers, ratios, rates, proportions, numbers expressed as percents, decimals, and fractions.

The student solves multi-step real-world problems involving fractions, decimals, and integers using appropriate methods of computation, such as mental computation, paper and pencil, and calculator.

The student applies formulas for finding rates, distance, time and angle measures.

The student knows a variety of strategies to estimate, describe, make comparisons, and solve real-world and mathematical problems involving measurements.

The student reads, analyzes, and describes graphs of linear relationships.

The student constructs and interprets displays of data, (including circle, line, bar, and box-and-whisker graphs) and explains how different displays of data can lead to different interpretations.

The student evaluates the hypothesis by making inferences and drawing conclusions based on statistical results.


-Graph Paper


Find the cost per Kilowatt Hour for your area.
Copy the worsheet for each student.
Have graph paper available.


Day 1:
1. Discuss with the students sources of light and how they are used .

2. Distribute the worksheet to the students.

3. The students will collect data needed to solve the
problems on the worksheet.

4. The students will solve all problems on the worksheet.

Day 2:
1. Divide the students into groups of four.

2. Students will compare the data from their worksheets and draw a multiple line graph comparing energy used by light sources for each person in the group.

3. Each group presents their graphs to the class and compares their graph to other groups.

4. Each student will write a brief summary describing the similarities and differences of household energy consumption and cost.


The students will be assessed by the evaluation of the graphs and the worksheet. Students who are having difficulty should receive feedback. As the students are working circulate around the room and observe for discussion and knowledge of how to solve the problems on the worksheet.


Local power companies could make a presentation on energy use to the students.

Attached Files

The worksheet for the students     File Extension: pdf

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