Logs, Loans, and Life Lessons!

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Students will be able to futher their knowledge of logarithms by applying them to dB's of sound. Students will compare sounds mathematically by using knowledge of exponential functions and logarithms.

Big Idea

This engaging lesson weaves together logarithms, loans, and life lessons!

Opening Discussion

15 minutes
Opening Discussion.docx page 1

Estimating the Age of a Vehicle

10 minutes
Estimating the Age of a Vehicle.docx page 1

Auto Loans and Exponential Decay

10 minutes

Not your "typical" Homework Assignment...

10 minutes

This is a homework assignment that the students literally can’t wait to get started!  I allow them to select their own vehicle, or “purchase” one from my “car lot” of cut strips from Cars.com.  I ask the students to be sure to pick a vehicle between $40,000 and $70,000.  In the assignment, the students are asked to graph the depreciation function for their automobile, as well as provide (and graph) a linear loan function that would be suitable for the purchase.  Although I encourage them to experiment with other down payments, I require them to put at least 20% down on the purchase price.  This is a really fun and insightful activity!!! 

Question #10 tells the students to be prepared to share their results with other students and teachers.  The next day, I like to put the kids in a situation where they can orally communicate their findings.  I have also gotten emails from parents in the past who talk about how neat it was to see their teenager bring home homework… AND actually WANT to talk about it!