Cell+phone+project+-+Linear+equations

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 * Title**: My Contract is Up… Who has the best deal?

//(You can ask students to research three particular companies before you start this lesson, be specific what they need to focus on).//
 * Description:** The activity gives the students information on three different cell phone companies and their information regarding the plans that are offered. They are to come up with the linear equations that represent the given data and then graph these equations. With the help of the graph (using their graphing calculators) they will be able to answer the several questions that are at the bottom of the handout.

Students will use their knowledge on graphing, equations, technology with the graphing calculators, y-intercepts, slope, intercepts between lines, intervals.
 * Learning Objectives:** Students will be able to use mathematical patterns, linear equations to describe real-life situations (using graphing calculator).


 * Duration**: 50 min (Activity might take 2 periods to complete)


 * Materials**: graphing calculators, graph paper


 * Procedures**
 * Students will be separated into groups of 2-3 (they will create their groups during warm-up activity)
 * Activity sheets will be handed out to students and followed with MINILESSON (Powerpoint) [[file:PPT cellphone project.ppt]]
 * Students will have approximately 5-6 minutes to come up with their equations
 * Teacher will discuss with students where the equations were derived from and make sure they have an understanding of what each element represents. Students will explain how they arrived to the solutions.
 * Teacher will work with the students to graph the functions in the calculators.
 * Students will have 5-10 minutes to replicate the graph on their individual graph paper.
 * Students will draw large graph on board representing the data and allow students to discuss with one another what the graph is representing.
 * Discuss the questions given in worksheet.
 * Each group member is to hand in their individual worksheet and graph.


 * Assessment**: RubiStar ( Scoring Rubric: **1437884)**


 * Grade level**: 9th grade

MST3.MR1: Students use mathematical reasoning to analyze mathematical situations, make conjectures, gather evidence, and construct an argument.
 * Related standards**

MST3.MM4: Students use mathematical modeling/multiple representation to provide a means for presenting, interpreting, communicating, and connecting mathematical information and relationships.

MST3.PF7: Students use patterns and functions to develop mathematical power, appreciate the true beauty of mathematics, and construct generalizations that describe patterns simply and efficiently.

MST3.alt.PF4: Students use mathematical patterns in a real-world situation.

ACTIVITY WORKSHEETS:

My Contract is up… Who Do I Choose!?

Your cell phone plan has just expired with Company X and you want to switch companies. Below is the information you gathered regarding the plans you are considering:

SPRINT has an initial monthly charge of $25.75 for providing their services and charges 30 cents for every minute.

VERIZON charges $55.50 per month and 10 cents for every minute.

CINGULAR does not have an initial monthly charge. It charges 75 cents for every minute.

Note: No more free minutes included in plans!


 * __TASK:__**

You decided to look deeply into this before making a decision. You are to create the following:

v Equations that represent each of your options v A graphical representation of the information you have gathered


 * __Answer the following questions:__**

v During what interval does SPRINT offer the best deal? v During what interval does CINGULAR offer the best deal? v During what interval does VERIZON offer the best deal? v Which company would you choose if you talked an average of 100 minutes per month? v What if you talked an average of 200 minutes per month? v When do SPRINT and VERIZON charge the same rate and what is that rate? v How do you chose which plan is best for you?

Have fun! =Worksheet Name:_= 1. A graphical representation of the information you have gathered (//One large graph per group)//

2. Equations that represent each of your options SPRINT: VERIZON: __CINGULAR:__

3. During what interval does SPRINT offer the best deal?

__4. During what interval does CINGULAR offer the best deal?__

5. During what interval does VERIZON offer the best deal?

__6. Which company would you choose if you talked an average of 100 minutes per month?__

_ __7. What if you talked an average of 200 minutes per month?__

_ __8. When do SPRINT and VERIZON charge the same rate and what is that rate?__

_

__9. How do you chose which plan is best for you?__ _