With a high interest topic, this activity graphs an exponential "decay" (depreciation) with a linear graph (car payments) and finds the intersection between the two graphs. Students groan when they watch their new cars "decay."

Prior to doing this activity, students should be familiar with graphing and setting a window for exponential decay models. The TI-Navigator™ portion is a screen capture which generates lively classroom discussion.

Provide a copy of the attached to each student.

After this activity, I assign students to price their "dream" new car and find appropriate financing. I usually give them 2 - 3 days to gather their data.
On the day that the assignment is due, each student graphs their data and we do a screen capture to compare cars!