Education Technology

# Activities

• ##### Subject Area

• Math: Algebra I: Data Analysis
• Math: Algebra I: Statistics
• Math: Algebra I: Equations and Inequalities

6-8
9-12

90 Minutes

• ##### Device
• TI-83
• TI-83 Plus Family
• TI-84 Plus
• TI-84 Plus Silver Edition
• ##### Other Materials
• Balsa wood sticks 1/8" x 1/8"
• Masses (200g. and 1,000g.)
• Fishing line
• Meter stick
• Scissors

## Breaking Up Over Model Bridges

#### Activity Overview

The learning objective of this activity is to introduce the concept of reciprocal functions having the form: xy = k or y = f(x) = k/x, where k is a constant and x and y are variables.

In Part I, twelve one inch paper squares arranged in various rectangles illustrate that length x width = 12 square inches. In Part II an experimental load constant is determined for a balsa wood cantilever: mass x failure length = k.

The TI-83/84 graphing calculator is used to display the three representations.

#### Before the Activity

Read the attached lesson plan, review the references, and gather the materials.

#### During the Activity

A student worksheet is provided in the attached lesson plan along with teacher notes and calculator screens to illustrate each step.

#### After the Activity

An extension activity, suitable for a statistics class, and a suggestion for an independent study project are included in the teacher notes.