Curriculum Unit
Now you see it, now you don’t: A unit to support eighth grade conceptualizations of size and scale through scientific notation applied to the electromagnetic spectrum
Allison Gantt
Title Author
KEY LEARNING, ENDURING UNDERSTANDING, ETC.
This unit aims to support students to build notions of size and scale beyond physical perception using the combination of a notational method (scientific notation) and knowledge of a new and critical context (the electromagnetic spectrum). The study of light involves microscopic wavelengths, incredibly fast speeds, and travel across long distances. The unit aims to supplement Illustrative Mathematics curricular materials about scientific notation with connections to this context and an emphasis on building new benchmarks for quantity, size, and scale.
ESSENTIAL QUESTION(S) for the UNIT
How can we visualize and compare the size and scale of large and small values through scientific notation, points of reference along the electromagnetic spectrum, and other landmarks in our world?
How does scientific notation simplify our calculations involving large and small values?
CONCEPT A CONCEPT B CONCEPT C
Viewing Distances with Light and Time
Frequency and the Speed of Light
The Size of Light Waves
ESSENTIAL QUESTIONS A ESSENTIAL QUESTIONS B ESSENTIAL QUESTIONS C
How can we use the speed of light to make sense of the time it would take to travel very large distances? How does scientific notation aid in this process?
How can we show through examples that the speed of light is constant using calculations involving wavelength and frequency? How does scientific notation aid this process?
How can number lines expressing powers of ten help us to visually compare the very small wavelengths that differentiate colors of light?
VOCABULARY A VOCABULARY B VOCABULARY C
Frequency; Scientific Notation; Hertz
Wavelength; Electromagnetic Spectrum; Powers of Ten
Light Year; Product
ADDITIONAL INFORMATION/MATERIAL/TEXT/FILM/RESOURCES
Illustrative Mathematics; NASA’s “Tour of the EMS”; BBC’s “What is a light year?”; Arcand, K., and M. Watzke, Light: The Visible Spectrum and Beyond.