Education Technology

# Activities

• ##### Subject Area

• Math: Algebra I: Linear Functions
• Math: Middle Grades Math: Algebraic Thinking
• Math: PreAlgebra: Linear Functions

6-8

60 Minutes

• ##### Device
• TI-73 Explorer™
• ##### Other Materials
This is Activity 3 from the EXPLORATIONS Book:
Activities for Algebra with the TI-73.

The following materials are required for this activity:
• Scale
• Wooden plank or meter stick
• Books
• Tape measure

#### Activity Overview

In this activity, students examine how moving a weight up along a board affects the downward force on the board. They explore how children with different weights can be balanced on a seesaw.

#### Before the Activity

• Position the scale and the block far enough apart so that the wooden plank is supported on one end by the scale and the other end by the block
• Starting at the edge of the scale, place marks at 10-cm increments on the wooden plank
• Set up the calculator for data collection using the procedure described in the attached Appendix PDF file
• See the attached PDF file for detailed instructions for this activity
• Print pages 25 - 37 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to the class.

• Place books at the 0 cm mark on the plank and record the weight
• Move the books to the 10 cm mark and record the weight
• Continue to move the books away from the scale in 10-cm increments and record weights
• Enter the data of distance and weight as a list
• Use this data to graph a scatter plot
• Visually estimate the trend line and find the line that contains as many points as possible
• Determine an equation for a trend line for the data, calculate the slope, and graph the trend line
• Find the weight of objects placed at different distances from the scale
• Find the distance from the scale given the object's weight shown on the scale

• Find a linear equation for the data
• View the graph of the best fit line
• Use the linear regression model, find weights at different distances, and find the distance given the weight
• #### After the Activity

Students will complete the Data Collection and Analysis page and answer questions.

Review student results:

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