Activity Detail
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A Penny Saved is a Penny Earned
 


Activity Overview

Students investigate exponential growth in powers of 2 and discover patterns in their sums.

Before the Activity

  • See the attached PDF file for detailed instructions for this activity
  • Print pages 111 - 116 from the attached PDF file for your class

    		•

    		During the Activity

    		Distribute the pages to the class.

    Follow the Activity procedures:
  • Find if it is better to take a lump sum of a million dollars, or take money, starting with a penny, with the amount doubling every day for 31 days
  • Use the constant function on the calculator to constantly double the previous amount
  • Use the calculator to compute the pennies paid each day and the cumulative total in dollars
  • Generate a list of days, pennies paid, and cumulative total
  • Create a scatter plot of cumulative total in dollars versus days
  • Adjust the window of the calculator and look at plotted data for 10 days, 15 days, and 30 days
  • Enter an equation that describes the graph
  • Observe that the graph increases exponentially
  • Create a graph for the amount $1,000,000, observe that it is a straight horizontal line
  • Examine the plan that doubles the amount every day and observe that it earns more than a million dollars after 27 days

    		After the Activity

    		Students will complete the Worksheet and analyze the results.

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

    		Other Downloads




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    view textbook alignment

    Subject Area:
    Math : PreAlgebra : Nonlinear Functions

    Author:
    Texas Instruments

    Level:
    5-8

    Activity Time:
    60 Minutes

    Device:
    TI-73 Explorer™

    Apps:
     

    Software:
     

    Accessories:
     

    Other:
    This is Activity 12 from the EXPLORATIONS Book:
    Discovering Mathematics with the TI-73: Activities for Grades 7 And 8



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