# Activities

• • • ##### Subject Area

• Math: PreAlgebra: Nonlinear Functions

• ##### Author 6-8

60 Minutes

• ##### Device
• TI-30X IIB
• TI-30X IIS
• TI-30Xa
• TI-34 II Explorer Plus™

Light Years Away

#### Activity Overview

Students develop models for a light year and compare numbers written in scientific notation and in standard notation.

#### Before the Activity

• Understand that light travels at 186,000 miles per second and that the distance that light travels in a year is called a light year
• See the attached PDF file for detailed instructions for this activity
• Print pages 42 - 44 from the attached Student PDF file for the class
• #### During the Activity

Distribute the pages to the class.

• Calculate how far light travels in a second, in a minute, in an hour, in a day, and in a year; and write the values in both, scientific and standard notations
• Determine the exact value of a light year and note the calculator key stroke sequence that gives this value
• Calculate the number of light years it would take Chris to travel a distance of 3000 miles each week for a period of 10 years
• Compute the number of trips one would need to make around the equator (circumference 24,000 miles) to travel 186,000 miles
• Find out how far a space-shuttle could travel in one year, if its speed is 17,500 miles per hour
• Determine the number of years it would take to reach the star Alpha Centauri, which is around 4 light years away from Earth
• #### After the Activity

Students complete the Student Activity pages.

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