Math Lesson: Illumination and Energy Efficiency
Lesson Plan
1 hour 15 minutesGrades9, 10, 11, 12Mathematics
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Written by Greta Stacy, Scott Anderson
About this lesson
Students investigate the lighting in the school’s halls, then take action and de-lamp a hall.
Inquire: Students examine three halls and classify them as too bright, too dim, or just right.
Investigate: Students measure the lux levels in three hallways and compare them to the industry standard.
Inspire: Students calculate the amount of money and CO2 emissions caused by overlighting a hallway and then de-lamp an overlit hallway.
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Suggestions
- This lesson ties in the real-world skills of calculating the cost of light levels and conserving energy to help our planet.
- This lesson could also be used in a chemistry or physics class when learning about light, as the math skills required for the lesson are also required in those disciplines.
Prerequisites
- Teacher can tease the lesson by turning on too many or too few lights in the classroom the day before.
- Students will need computers to do some quick research in the lesson.
- Students will need to know the wattage of the light bulbs in the hallways they visit. This may require pre-arrangements with the school’s maintenance team. Or, students can assume the bulbs are about 20 W each.
- Before the lesson, teacher should decide how students will measure lux and prepare accordingly.
- Students can use a Vernier light sensor or a similar light sensor to measure lux.
- Students can use their smartphones to measure lux. The following apps are free:
Differentiation
- Students can work in teams to present their findings and explain the supporting mathematics.
- Students can create visual and oral presentations summarizing their findings and suggestions and present them to the school administration or other audiences.
- After sharing all suggestions, students can vote on the top suggestion and explain why.
- Students can interview the school’s maintenance department to learn how hallway lighting is determined.
From the scientist review
This lesson allows students to learn about the climate justice issues regarding efficient lighting and ways to measure and account for carbon footprint from lighting inefficiencies and inequities. After review, we found this lesson to be credible in terms of science.
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About the teacher writers
Greta Stacy
Education Specialist
Greta Stacy holds a Bachelor of Chemistry from Smith College, a Master of Teaching from Hamline University, and a Graduate Diploma in Chemical Engineering from the University of Limerick. She has nine years of experience teaching chemistry, science, and mathematics for grades 9–12. Greta holds a Minnesota 9–12 Chemistry teaching license, UK Qualified Teacher Status (QTS), Irish Teaching Council registration, and certifications in International Baccalaureate Chemistry and Advanced Placement Biology.
Scott Anderson
Scott Anderson holds a Bachelor of Science in Mechanical Engineering from the University of Wisconsin–Platteville and a Master's degree in Instruction from Saint Mary's University of Minnesota. He has been teaching STEM for grades 9–12 since 2006, bringing prior industry experience as an engineer into the classroom to connect learning with real-world applications. Scott holds a Wisconsin Lifetime Teaching License and leads hands-on sustainability initiatives as the Wisconsin Green Team advisor, while supporting climate education as a lesson author for SubjectToClimate.
