Characteristic of Learning: Authentic

Level of Technology Infusion Into the Curriculum: Adoption

Lesson Title: Calculating A Monthly Car Payment

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Grade Level: 11-12

Classroom Configuration

One to one, using classroom computers or mobile laptops as rotating stations

Common Core State Standards: Mathematics

Mathematical Practices

  1. Make sense of problems and persevere in solving them.
  2. Reason abstractly and quantitatively
  3. Use appropriate tools strategically

Statistics and Probability

Interpreting Categorical & Quantitative Data: Summarize, represent, and interpret data on a single count or measurement variable.


Use statistics appropriate to the shape of data distribution to compare center (median, mean) and spread (inter-quartile range, standard deviation) of two or more different data sets


Understand solving equations as a process of reasoning and explain the reasoning.

1. Explain each step in solving a simple equation as following from the equality of numbers asserted at the previous step, starting from the assumption that the original equation has a solution. Construct a viable argument to justify a solution method.

Arizona Educational Technology Standards (2009)

  • Strand 4: Critical Thinking, Problem Solving, Decision Making
    • Concept 1:Investigation,
      • PO 1 Plan and manage data sets from diverse sources, creating planning adjustments and course corrections from knowledge gained.
  • Strand 5 Digital Citizenship
    • Concept 1: Safety and Ethics,
      • PO 3 Advocate and practice safe, legal and responsible use of digital tools as defined by school board polices and procedures


  • The students will solve a real-world problem of calculating a monthly car payment by utilizing online tools.
  • The students will calculate a monthly car payment by using a formula containing fractions, exponents, and order of operations from information acquired via online resources.


  • Students will research a car from an Internet used car dealer. Example sites to use:, AutoTrader, carmax
  • Once students find a car, they will use the formula below to calculate a monthly payment.
    • Students will experiment with the interest rates 6%, 8%, and 10%
    • Students will also experiment with a 3 and 4 year loan length
    • Students will calculate payment assuming there is no down payment, so the student must finance the entire price of the car.
    • Key for formula: p = principal, r = interest rate, m = monthly payments
  • example calculation for a 3 year (36 month loan) of $14,000 at 6% interest would look like this:
  • The payment for this car would be $ 425.91

  • Students will use an online scientific calculator, if scientific calculators are not available


  • Students will write down the setup for each loan configuration that they compute and explain how they arrived at their answers.
    • Loan Configurations will be:
      • 3 year loan at 6% interest
      • 4 year loan at 6% interest
      • 3 year loan at 7% interest
      • 4 year loan at 7% interest
      • 3 year loan at 8% interest
      • 4 year loan at 8% interest
  • Students will create a spreadsheet with the information via Google Tools or Zoho.
  • The students will answer the following questions:
    • Which car is the best deal? Defend your answer.
    • Which car would you be most likely to purchase, why?



  • Student work will be assessed by evaluating the calculations that students computed and their responses to the questions.

Extension: Have students do a comparison of cost between two cars they would most like to own. Record data in a spreadsheet program. They should include items to reflect total cost of ownership.


Technology Integration Matrix





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