Education Technology

# Activities

• ##### Subject Area

• Math: PreAlgebra: Geometry

6-8

60 Minutes

• ##### Device
• TI-73 Explorer™
• ##### Other Materials
• Colored pencils - red and green
• Metric ruler
• Compass
• Tracing paper and graph paper

• This is activity 8 from the EXPLORATIONS Book:Activities for Algebra I with the TI-73.

## At a Snail's Pace for the TI-73 Explorer™

#### Activity Overview

It is hard to imagine a way to mathematically describe a spiral. Spirals are commonly seen in nature. There are a number of different types of spirals. Some interesting examples include the spiral arrangements of scales in pine cones, seeds in a sunflower, or the calcified layers of a snail's shell. One way of constructing a spiral is to use the Fibonacci sequence.

#### Before the Activity

• Review the attached PDF
• Print the attached PDF file for your class
• #### During the Activity

Students will:

• Plot a mathematical relationship that defines a spiral
• Use technology to create a spiral similar to that found in a snail
• Use technology to plot a set of ordered pairs
• #### After the Activity

Review student results:

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