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Learning Math Home
Patterns, Functions, and Algebra
Session 7 Part A Part B Part C Part D Homework
Algebra Site Map
Session 7 Materials:

Session 7, Part B:
Exponential Growth (40 minutes)

In This Part: A Salary Situation | Population Growth

Suppose you are given two different options for salary at a temporary job. Note 5

Plan A: 

You can earn $2,000 each week, or

Plan B: 

You can earn 1 penny the first week, 2 pennies the next week, 4 pennies the next week, and so on, doubling your salary each week.

The job lasts 25 weeks, and your goal is to earn the largest total salary for the 25 weeks.

Problem B1


Which salary plan would you choose and why? Write down your initial reaction.


Problem B2


Use a spreadsheet or some other method to figure out which salary plan is better.

Stop!  Do the above problem before you proceed.  Use the tip text to help you solve the problem if you get stuck.
When using a spreadsheet, create three columns, one for the week number, one for plan A, and one for plan B. When creating the rule for plan B, remember that the salary is doubling each week, and that the first week's salary is one penny, not one dollar.    Close Tip


Problem B3


Are you surprised that the second salary grew so rapidly? Use the spreadsheet to determine how much money you would make from plan B in 40 weeks.

Stop!  Do the above problem before you proceed.  Use the tip text to help you solve the problem if you get stuck.
To make a column wider, click and hold down on the right edge of the column heading letter, then drag the mouse to the right.   Close Tip

video thumbnail

Video Segment
In this video segment, on screen participants discuss the differences between salary plans A and B in Problems B1 and B2 above. In particular, they explore the differences between linear and exponential functions. Watch this segment after you have worked on Problems B1 and B2. If you get stuck, you can watch the video segment to help you.

Describe the difference in the ways salary plans A and B grow. Which one is a proportional change, and which is an absolute change? For more on this, see Session 4, Part A

You can find this segment on the session video, approximately 7 minutes and 51 seconds after the Annenberg Media logo.


Next > Part B (Continued): Population Growth

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