In this lesson, students examine inputs and outputs from functions. After a Warm-up riddle in which students guess the function from inputs and outputs, students then think about pairs of variables and determine which variable is likely the input. In the last activity, students think about possible inputs for given function descriptions.

In the associated Algebra 1 lesson, students begin to learn about the domain and range of a function. Students are supported in this lesson by concentrating on inputs and outputs for functions and thinking about what might be possible for each.

Students must reason abstractly and quantitatively (MP2) when they interpret possible inputs and outputs from given functions and then invent a few examples of their own.