Math Lesson Plan · Grades 6–9

Function Machines Lesson

Introduce students to functions using the function machine model. The lesson teaches function vocabulary, how to write function rules, and how to complete function tables by applying rules to input values. Includes 20 practice problems and answer key.

Lesson Overview

Understanding Functions with Input/Output Machines

A function machine takes an input, applies a rule, and produces an output. The rule is the function — for example, “multiply by 3 then add 1.” Once students understand the machine model, they can write the rule algebraically and use it to complete function tables.

The eight-page lesson introduces function vocabulary, demonstrates the function machine model, and shows how to write and apply function rules. Students complete 20 practice problems and check their work using the answer key on page 8.

How to Use This Lesson

1. Review patterns and introduce function vocabulary (pages 1–2). Introduce input, output, and function rule using the machine analogy.

2. Practice writing function rules and completing function tables together (pages 3–6). Connect the machine model to algebraic notation.

3. Assign the 20 practice problems (page 7) independently. Review answers using the key on page 8.

Printable Resource

A classroom-ready PDF with everything in one printable resource.

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