Linear Function Book
Objectives:
 Students will explore linear functions in a real world setting
 Students will look at multiple representations of a function
The Activity:
1. Write a story problem that can be represented by linear function.
2. Write the linear function that goes with your story.
3. Write your linear function in another form.
4. Find 5 ordered pairs that satisfy your function. Display the ordered pairs in a
table. Pick one ordered pair and describe what it means in the context of your
problem.
5. Draw a graph of your function. Think about what input and output values
make sense to your problem. Label the x-axis and y-axis. Title the graph.
6. Identify the slope and intercepts and describe what each means in the context
of the problem.
7. Write 3-5 sentences reflecting on how you know your results are accurate and
make sense in the context of your problem. Explain the importance of your
findings in connection to real-life. Reflect on your method, what worked well for
you and what would you change?
Criterion C. Communication in mathematics
Achievement Level
0
Level Description
The student does not
reach a standard
described by any of the
descriptors below.
Items
1-2
The student shows basic
use of mathematical
language and/or forms of
mathematical
representation.
Student either does not
identify slope and/or
intercepts or identifies
slope and/or intercepts
incorrectly.
The lines of reasoning are Variables are defined and
difficult to follow.
labeled on graph or table.
The student accurately
displays function as 2 of
the following: story,
table, graph and 1
equation.
3-4
The student shows
sufficient use of
mathematical language
and forms of
mathematical
representation.
The lines of reasoning are
clear though not always
Student identifies slope.
logical or complete.
Student identifies the
intercepts.
The student moves
between different forms
Variables are defined and
of representation with
labeled on graph and
some success.
table.
The student accurately
displays function as a
story, table, graph and 1
5-6
equation.
The student shows good
Student identifies slope
use of mathematical
and describes the rate of
language and forms of
change. Student
mathematical
identifies the intercepts
representation.
and describes meaning in
the context of the
The lines of reasoning are problem.
concise, logical and
complete.
Independent and
dependent variables are
The student moves
clearly defined and
effectively between
labeled on graph and
different forms of
table.
representation.
The student accurately
displays function as a
story, table, graph and 2
equations.
Criterion D: Reflection
Achievement Level
0
1-2
3-4
5-6
7-8
Level Descriptor
Items
The student does not
reach a standard
described by any of the
descriptors below.
The student generally
makes appropriate
deductions when solving
simple problems in
familiar contexts.
The student generally
makes appropriate
deductions when solving
more complex problems
in familiar contexts.
The student generally
makes appropriate
deductions when solving
challenging problems in a
variety of familiar
contexts.
The student consistently
makes appropriate
deductions when solving
challenging problems in a
variety of contexts
including unfamiliar
situations.