Education Technology

# Activities

• ##### Subject Area

• Math: Algebra I: Quadratic Functions

6-8

60 Minutes

• ##### Device
• TI-30X IIB
• TI-30X IIS
• TI-34 II Explorer Plus™
• ##### Other Materials
This is Activity 8 from the EXPLORATIONS Book:
Math Investigations with the TI-30X IIS and TI-34 II: Activities for the Middle Grades

You will need the following materials for this activity:
• Geoboards
• Rubber bands

## Storefront Signs

#### Activity Overview

Students learn to find area and explore the quadratic function. They compare the areas and patterns of squares within a square.

#### Before the Activity

• See the attached PDF file for detailed instructions for this activity
• Print pages 71 - 77 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to the class.

• Draw all possible designs of the square sign in the display window, or construct models using geo boards
• Record all possible positions of the hooks from the corners
• For each position, determine the area of the four small triangles surrounding the square, the length of one side of the square, and the area of the square
• Record the area values in a table
• Observe that the results are pairs of squares with the same area [except one value]
• Plot a graph of Area versus Distance
• Note that the areas get smaller and then get larger
• Notice that the differences in the areas of successive squares diminish and then grow again
• Observe that the graph is a parabola
• Use the graph to determine the area of the largest possible sign and the smallest possible sign
• #### After the Activity

Students complete the Student Activity pages and answer questions.

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