Proportional Relationships & Linear Functions

Explore the connection between proportional relationships and linear functions, including slope and y-intercept.

Grade 6-8Intermediate55 min

About This Lesson

In this lesson you'll discover how linear functions create straight lines, and how slope and y-intercept describe everything about those lines. You'll connect tables, graphs, and equations — and use them to model real-world situations.

Essential Question

Plot the points (0,1), (1,3), (2,5), (3,7) on a coordinate plane. What pattern do you notice?

Standards

CCSS 8.F.A.3, 8.EE.B.5, 8.EE.B.6

Learning Objectives

1Identify slope as the rate of change in a linear relationship
2Graph proportional and non-proportional linear equations
3Write equations in slope-intercept form y = mx + b

Materials Needed

Graphing paper
Rulers
Colored pencils
Slope triangle cutouts

Key Topics

linear functionsslopey-interceptgraphingalgebra