Let's Talk


In this activity you will be asked find out the cost of Jane's cell phone plan. You will need to be able to interpret, write, and solve equations.


Jane’s cell phone plan is $40 per month plus $.15 per minute for each minute over 200 minutes of call time. If Jane’s cell phone bill is $58.00, for how many extra calling minutes was she billed?

Task 1: Read and Understand

  1. Explain how the amount of Jane’s phone bill is determined?
  2. What is the problem asking you to determine?

Task 2: Plan and Solve

    3. What would Jane’s phone bill be if she talked for exactly 200 minutes?

    4. What would Jane’s phone bill be if she talked for 10 extra minutes? 

    5. Fill in the table below to help write your own equation.

Variable Expense
 Base Total Expense = 58.00?
 0.15(0)     40 0.15(0) + 40 = 58 ?
 0.15(10) 40 
Continue filling in the table until you find the correct answer. Use the table to write an equation. 


    6. Use your equation to determine how many extra calling minutes Jane was billed for if her phone bill was $58.00.

    Task 3: Look Back and Check

        7. Is this a reasonable plan? How many minutes do you talk on the telephone each month? Is it reasonable to allow 200 minutes before charging extra?                                 

    Task 4: Solve Another Problem

        8. Janet’s cable company charges her a basic fee of $59. For each premium channel, she is charged an extra $12. How many premium channels does she have if her total bill is $107 each month?