options: Understand that a function is a rule that assigns to each input exactly one output. The graph of a function is the set of ordered pairs consisting of an input and the corresponding output. (Function notation is not required in Grade 8.)

Interpret the equation y = mx + b as defining a linear function, whose graph is a straight line; give examples of functions that are not linear. For example, the function A = s2 giving the area of a square as a function of its side length is not linear because its graph contains the points (1,1), (2,4) and (3,9), which are not on a straight line.

Compare properties of two functions each represented in a different way (algebraically, graphically, numerically in tables, or by verbal descriptions). For example, given a linear function represented by a table of values and a linear function represented by an algebraic expression, determine which function has the greater rate of change.
problem_activity: Activity
In this partner activity, students take turns finding a set of representations that represent the same function. As students trade roles explaining their thinking and listening, they have opportunities to explain their reasoning and critique the reasoning of others (MP3).
Launch
Arrange students in groups of 2. Partners take turns identifying representations that match, and explaining to their partner how they know they match. If necessary, demonstrate the protocol before students start working, including productive ways to agree or disagree, for example, by explaining your mathematical thinking or asking clarifying questions.
Student Facing
Your teacher will give you a set of representations. Sort them so that in each group there is a table, graph, equation, and example that all represent the same function.
Student Response
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Activity Synthesis
Much of the discussion will happen within groups. Ensure that students found correct matches, and invite selected students to explain how they know they are matches. Here are some possible discussion questions:
“Which matches were tricky? Explain why.”
“Did you need to make adjustments in your matches? What might have caused an error? What adjustments were made?”


correct_option_index: 2