Education Technology

Phases of the Moon

Activity Overview

In this TI InterActive!™ activity, students study the phases of the moon, plot the fraction of the moon showing each day in a month, and fit the data with an appropriate trigonometric function.

Before the Activity

  • Install the TI InterActive!™ on the computer
  • Print the page from the attached file for the class
  • During the Activity

    Distribute the printed page to the class.

    Follow the Activity procedures:

  • Identify the eight recognized stages in the lunar cycle
  • Use the Internet to find the approximate period of the moon's cycle
  • Determine the fraction of the moon showing for the days of the year
  • Set up a scatter plot of the fraction of the Moon showing in January versus the day of the year
  • Observe the graph and determine the amplitude and the vertical translation
  • Find a cosine and a sine function which fits the data
  • Identify the phase shift for the function
  • Repeat the steps for the fraction of moon showing in January and February
  • After the Activity

    Students answer questions on the activity page.

    Review student results:

  • As a class, discuss questions that appeared to be more challenging
  • Re-teach concepts as necessary