Lesson objective: Relate behaviors of a function to a real-world situation.

This lesson provides an opportunity for students to apply their knowledge and understanding of behaviors of a function to a real-life situation. Students are asked to describe the pay rate of a lawn-mowing job, represent a second pay option, and determine which pay plan is better.

Key Concept students will use:

- Graphing input-output pairs helps us describe and model the behavior of a function qualitatively.

Skills students will use:

- Understand behavior of a function given as a graph of the function
- Model the behavior of a function given a description of the function

Students engage in Mathematical Practice 2 (reason abstractly and quantitatively) and Mathematical Practice 4 (model with mathematics) as they examine input-output pairs to understand, describe, and model the behavior of a function.

**Key vocabulary: **

- constant
- decreasing
- function
- increasing