Lesson objective: Identify nonlinear functions based on tables and graphs.

This lesson helps to build fluency with finding rates of change to determine linearity. Tables and graphs are used here because those are two of the representations with which students need to become fluent. This work develops students' understanding that not all functions are linear.

Students engage in Mathematical Practice MP.5 (use appropriate tools strategically) as they decide whether to use a table or a graph to investigate rates of change. Is one representation easier to analyze than another? A point on graphs may be harder to read than in tables, so students should think about which representation gives a mathematically precise answer.

**Key vocabulary:**

- function
- linear
- nonlinear
- rates of change

**Special materials needed:**