Education Technology

Finding the GCF

Published on 06/09/2008

Activity Overview

Students simplify fractions by dividing the numerator and denominator by the GCF (the greatest common factor). They check their work by using a calculator.

Before the Activity

  • Set up the calculator as explained in the appendix file
  • See the attached PDF file for detailed instructions for this activity
  • Print the pages from the attached PDF file for the class
  • During the Activity

    Distribute the pages to the class.

    Follow the Activity procedures:

  • Without using the calculator, find the greatest common factor for the given fractions


  • Enter the fraction and use the simplify function
  • Note the new fraction displayed along with the factor used for simplification of the numerator and denominator
  • Continue to simplify the fraction further till it can be no longer simplified
  • Note all the factors used to simplify the fraction, and multiply the factors to get the GCF
  • Verify the value of the GCF by entering the original fraction, using the simplify function key, and the GCF value to get the simplified fraction
  • Find the GCF of the other fractions listed
  • After the Activity

    Review student results:

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