8th Grade Task: Sally's Car Loan

Essential and guiding questions:

Is the correct answer 27.63 or 39.63 months?
Can you round off your answer in this problem?
What is the meaning of the decimal part of your answer?
What would the last payment be?
What if the problem had talked about Sally paying 4% interest on the amount she borrowed?
How can there be a line with positive slope and a line with negative slope that can represent this situation?
Can you come up with equations of lines for the two equations?
Find a way to verify that these equations are correct.

Blooms taxonomy level:

Understanding

Differentiation suggestions:

If students can’t get started….
Assessing

How much was the car? How much money did Sally pay for a down payment? How much does she owe when she drives off the lot?
How much did she pay off in the first 12 months?

Advancing

How can we use this to help us with how long it will take her to pay off the car?

Extension suggestions:

If students finish early….
Assessing

Advancing

Come up with another graph that would work for this situation. Follow the directions for part B.

Originator: