Education Technology

Betweenness and the Sum of Parts

Published on 06/09/2008

Activity Overview

In this activity, students' will explore the concepts of betweenness and the sum of parts visually, geometrically, and numerically for segments and angles using the Cabri® Jr. application. They will investigate how the sum of parts equals the whole.

Before the Activity

  • Install the Cabri Jr. App on the students' graphing calculators using TI Connect™, a TI connectivity cable, and the unit-to-unit link cables
  • Use the TI-Navigator™ to transfer the attached Cabri Jr. AppVar files to each calculator
  • See the attached PDF file for detailed instructions for this activity
  • Print pages 3 - 5 from the attached PDF file for your class
  • During the Activity

    Distribute the pages to your class.

    Follow the Activity procedures:

  • Use the AppVar to go directly to the exploration section
  • Draw and label a segment and a point on the segment
  • Measure the length of the segments
  • Change the position of the point and observe the change in the measures and note how they are related
  • Draw segments to form adjacent angles
  • Measure the angles formed
  • Change the position of the segment and observe the changes in the measures and note how they are related
  • After the Activity

    Review student results

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