Let Your Fingers Do the Talking Performance Assessment – Algebra II/Trigonometry Unit 2
Teacher Description of Task:
Goal:
Role:
Audience:
Situation:
Product(s):
Standards &
Criteria for
Success:
Determine the best text messaging plan to fit the needs of various cell phone clients.
Students will take on the role of a cell phone company representative.
Clients of the cell phone company will be the audience for this task.
Each student will be assigned to one of four cell phone companies, for which the basic rates for text
messaging are provided. Each student will create a graph depicting the costs of the company for
which he or she has been assigned and analyze the text message plans that might best suit
particular customers.
The student will create a written sales pitch that describes the text messaging plans of the company
for which he or she is assigned. The sales pitch will be accompanied by a piece-wise graph showing
the costs of the various types of text messaging plans. The student will then be expected to present
their plan to others. The students will then be presented with possible clients with different text
messaging needs and be asked to determine the best plan to suit the client’s needs. Students will
complete a written reflection of the task and the process used to analyze the plans.
MA.9-12.MA.A2.2.3: The student will recognize multiple representations of step functions and be
able to determine the domain and range of a step function, graph using a transformational
approach and a graphing calculator, and write an equation of a step function given a graph or table
of values (SOL AII.8).
Students will present a written description of the various text messaging plans, a chart describing
them, a piecewise function graph with corresponding equations, written client suggestions, and
completion of reflection questions.
Teacher notes:
-
-
The curricular focus of this task is based upon modeling real world data using piece-wise functions. Students will
analyze the plans of one company to create a piecewise function graph and equation using the data provided.
Encourage students to examine the domain of the function being graphed to ensure that the graph accurately
reflects the various plans available. Does the domain of the function have open or closed endpoints? What is
the independent and dependent variable of the function?
Students may struggle with creating a “sales pitch” and may need specific information about what this means.
Students should be encouraged to use appropriate mathematical terminology when providing explanations in
the task.
Let Your Fingers Do the Talking Performance Assessment
Algebra II/Trigonometry Unit 2
You are a representative of a cell phone company and will describe your company’s text
messaging plans in a written and verbal presentation and help clients to decide which text
messaging plan would be best suited to their needs. You will be assigned as a sales person
for one of the following four cell phone companies: AT&T, Verizon, Sprint, or
T-Mobile.
Your supervisor has asked you to create a written presentation of the various text messaging plans for your company
including:

A description of each text messaging plan

A piecewise function graph depicting each plan

A piecewise equation representing the various plans

Persuasive information about why your company offers the best services
You will present your plan to a group of sales persons from other companies. You will then be assigned three clients (a
description of each client will be provided on an index card) and will determine which company’s text messaging plan
best meets each client’s needs. A written reason for which plan was chosen will be required for each client.
You will then be asked to provide written explanations to the task reflection questions shown below:
1. Why is the data included in the text messaging plans best modeled by a piecewise function?
2. What representation of your text messaging plans is best suited to explain your costs to potential clients? Why?
3. Do any of the plans for your company overlap one another? How is this represented in the graph? How is this
represented by the equation?
4. Consider how many text messages you send in one day and multiply that by 30. Which plan would best fit your
needs? Approximate your cost per text message.
AT&T
TEXT MESSAGING PLAN
Messaging – 200 texts per
month
Messaging – 1500 texts
per month
Messaging – unlimited
Messaging - Pay per use
SPRINT/NEXTEL
COST PER MONTH
$5.00
$15.00
$20.00
$0.20 per text
message/instant message
$0.30 per picture/video
message
TEXT MESSAGING PLAN
Messaging – 300 texts per
month
Messaging – 1000 texts
per month
Messaging – unlimited
Messaging - Pay per use
COST PER MONTH
$5.00
$10.00
$10.00 with a Power Pack
Plan
$15.00 with other Cell
Plans
$0.20 per text
message/instant message
Verizon Wireless
TEXT MESSAGING PLAN
Unlimited Plus 500 – 500
text messages per month
plus unlimited mobile to
mobile minutes
Unlimited Plus 1500 –
1500 text messages per
month plus unlimited
mobile to mobile minutes
Unlimited Plus 5000 –
5000 text messages per
month plus unlimited
mobile to mobile minutes
Messaging - Pay per use
COST PER MONTH
$10.00
$15.00
$20.00
$0.20 per text
message/instant message
$0.25 per picture/video
message
ALLTEL
TEXT MESSAGING PLAN
Messaging – 200 texts per
month
Messaging – 400 texts per
month plus unlimited
mobile to mobile minutes
Messaging – 1000 texts
per month plus unlimited
mobile to mobile minutes
Messaging – unlimited
plus mobile web and data
minutes
Messaging - Pay per use
COST PER MONTH
$4.99
$7.99
$12.99
$19.99
$0.15 per text
message/instant message
$0.25 per picture/video
message
Let Your Fingers Do the Talking Performance Assessment Rubric
Algebra II/Trigonometry Unit 2
Level
Expert
4
Practitioner
3
Emerging
2
Novice
1
Multiple
Representations
Graph is completely:
accurate
neat
easy to understand
labeled;
scaled to reflect data
provided.
Graph is generally:
accurate
neat
easy to understand
labeled;
scaled to reflect data
provided.
Minor discrepancies do not
affect overall result.
Graph is partially:
accurate
neat
easy to understand
labeled;
scaled to reflect data
provided.
Numerous errors detract
from result.
Graph is not completely:
accurate
neat
easy to understand
labeled;
scaled to reflect data
provided.
Significant errors detract
from result.
Application
Sophisticated
interpretation is evident in
the explanation.
Interpretation of the
problem is accurate.
Interpretation of some of
the problem is correct, but
key elements are missed.
Communication
Sales pitch is exceptionally
clear with a thorough
analysis of data.
Sales pitch is generally
clear with a substantial
analysis of data.
Sales pitch lacks clarity
and is difficult to follow.
Reflection
Reflection is connected to
prior knowledge or
learning.
Extension of learning is
consistently evident
through reflection.
Reflection is connected to
prior knowledge or
learning.
Extension of learning is
frequently evident
through reflection.
The reflection rarely uses
prior knowledge or
learning.
Extension of learning is
not consistently evident
through reflection.
Reflection is not
connected to prior
knowledge or learning.
Interpretation of the
problem is incorrect.
Sales pitch is unclear with
a limited analysis of the
data.
Extension of learning is
not evident through
reflection.
Client List
Age is: 10 years old→ This is the customer’s first cell phone and will only be allowed to use it to contact his parents or
in an emergency. Texting is allowed but only in the above circumstances.
Age is: 81 years old→ This customer will most likely only use texts to communicate with her grandkids.
Age is: 73 years old→ This customer only uses his cell phone for emergencies.
Age is: 25 years old→ Texting is the main form of communication for her.
Age is: 19 years old→ He texts frequently but is on a strict budget so needs to spend as little as possible.
Age is: 39 years old→ This working mom will mainly text will her teenage children although some of her friends
communicate through texts.
Age is: 55 years old→ He texts with his wife and adult children occasionally.
Age is: 15 years old→ She texts constantly because then she is able to have multiple conversations going
simultaneously. Her parents are on a budget.
Age is: 43 years old→ Reads texts that are sent to him but does not text back.
Age is: 28 years old→ Texting is her main form of communication but she recently lost her job so she needs to have the
most economical plan that fits her needs.
Age is: 10 years old→
Age is: 81 years old→
This is the customer’s first cell phone and will
only be allowed to use it to contact his
parents or in an emergency. Texting is
allowed but only in the above circumstances.
This customer will most likely only use texts to
communicate with her grandkids.
Age is: 73 years old→
Age is: 25 years old→
This customer only uses his cell phone for
emergencies.
Texting is the main form of communication
for her.
Age is: 19 years old→
He texts frequently but is on a strict budget
so needs to spend as little as possible.
Age is: 39 years old→
This working mom will mainly text will her
teenage children although some of her friends
communicate through texts.
Age is: 55 years old→
Age is: 15 years old→
He texts with his wife and adult children
occasionally.
She texts constantly because then she is able
to have multiple conversations going
simultaneously. Her parents are on a budget.
Age is: 43 years old→
Reads texts that are sent to him but does not
text back.
Age is: 28 years old→
Texting is her main form of communication
but she recently lost her job so she needs to
have the most economical plan that fits her
needs.