Lesson Plan

Introduction to Functions

8th Grade Introduction to Functions including Domain and Range
Christine T.
Classroom teacher
Webb Bridge Middle School
Alpharetta, United States
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My Grades 6, 7, 8
My Subjects Math

This lesson is intended to span one to two 50 minute periods as an introduction to functional relations. It is designed for the 1:1 classroom but can easily be adapted for classes with fewer devices since not all students need to be on technology at the same time. Students should have background knowledge of linear equations, including how to determine slope, graphing lines given a variety of information (including 2 points, slope and 1 point, one point and the y intercept, etc) prior to beginning this lesson.

This lesson begins with a fun video to introduce students to a function machine. The preceding and followup discussions help students to relate a familiar situation to the concept of functions. As the lesson progresses students work their way through a Power Point presentation with the teacher, taking notes along the way to gain familiarity with domain and range, function notation, and beyond to the vertical line test. For this lesson, only the first 6 slides are used. The remaining are saved for follow up lessons. 

The learning continues with a review of input and output tables using the Shodor interactive website. Function tables are not new to students, although the name is unfamiliar. Students practice determining the function rule after putting a value as the input and receiving an automated output. Students will develop strategies for identifying patterns.

Those students who quickly grasp the skill may continue to practice independently on the Shador Interactive and ultimately move on to play Prodigy Game to practice the concepts of this lesson. Those who need more remediation will continue to work with the teacher to determine the function rules.

In closing, the ticket out the door uses Socrative to quicky assess student understanding of today's learning objective, "What is a function?"

Long Term Creative Project: Students will be assigned a unit project to be due/presented prior to the summative assessment for this unit. Students will be given a choice of technolgy tools to use and introduced to Glogster as a possible option. Guidelines are intentionally minimal and are included in the rubric on Rubistar.


Students will understand what makes a relation a function.

Students will understand how patterns relate to functions.

Students will understand how sets of numbers are related to each other.


What is a relation?

What makes a relation a function?

How can I describe mathematical patterns using function notation?


Grades 7 – 9
All Notes
Teacher Notes
Student Notes

1 Hook

BEFORE SHOWING VIDEO POSE THIS SCENERIO: If your mom goes to the market and purchases some chicken, what kinds of dinners might she make? Ask students to turn and talk.

Show video.


Consider the chicken dinner situation, in order for dinner to fit the function rule, what must happen? What do you think a function is?

2 Direct Instruction

Using the Power Point, introduce students to relations and functions including the concepts of domain and range. Stop at slide 6.

Have students take notes for reference.

Student Instructions

Students, use your interactive notebook and take notes during the PPT presentation.

Title your page INTRODUCTION TO FUNCTIONS and add it to your Table of Contents.

3 Guided Practice

Work through the first several problems on the Shodor interactive activity together. As students demonstrate understanding, have them move to independent practice.

For those students who need more support, continue to work with them, having students write their solutions on white boards to share with each other.

4 Independent Practice

Free, Paid

Allow students to practice on Prodigy Game for approximately 25 minutes.

If students are not ready to move to independent practice, continue to work on the Shodor interactive together.

Student Instructions

Students, you have 25 minutes to play Prodigy Game. 

When you have completed 25 minutes, come get the Ticket out the Door from me.

5 Ticket out the Door

Free, Paid

Have students join room F8CHK0F3 and answer the ticket out the door before leaving.

Student Instructions

Students, answer the Ticket out the door. Keep in mind there may be more than 1 correct answer.

6 Enrichment Follow Up

Free to try, Paid
Free to try, Paid
Prezi Next
Free, Paid

Demonstrate the sample presentation using Glogster (or similar technology). Explain to students that they will be responsible for creating a Glogster poster of their own (or similar presentation using a tool of their choice to be approved by me), following the requirements described in the rubric. Review the rubric and assign due date to align with the summative assessment.

Allow students who need more support to work with an assigned partner.

Student Instructions

Students, you challenge is to create an online, interactive poster using Glogster, or a presentation tool of your choice (to be approved by me). Your presentation must use a minimum of 3 different kinds of multimedia (videos, games, quizzes, VR, etc) to explain what you have learned about functions during this unit. This project will be due prior to the summative assessment and will need to be uploaded to our website. 

The rubric is found at the following link