Cell phone plans

Its time to go get the latest iPhone, the 5s. Which of the above plans will you choose? Should you sign a 2-year contract on one of the above plans to get the iPhone for $200? Or should you go through T-Mobile, pay $648 for the phone and $60 a month for 3 GB of data?

This lesson makes a great intro to linear relationships. Student pick one plan and consider the cost of the phone and plan over time. They make tables, graphs and equations. Consider allowing students to begin playing with the task without much initial direct instruction. Guide them with good questioning and teach after they have had time to grapple with these questions and construct new ideas.

After students select a plan and complete their graphs consider posting the graphs up on the wall (or over a document camera). Have the rest of the class identify which cell phone deal matches their graph. Finally students compare paying for the phone up front with T-Mobile versus going with a contract. Which is cheaper over the long run?

Throw in some technology by having students compare plans using this Desmos graphing calculator app for this lesson. This is a great way to introduce or review linear equations.