Unit 5, Lesson 5
Comparing Relationships with Equations
Accelerated 6
Preparation
Lesson Narrative
In this lesson, students examine equations of proportional and nonproportional relationships. They use the equation to complete a table of values and then divide the pairs of values on each row to determine whether the relationship is proportional. The focus is on looking for structure, seeing the connection between the form of the equation and the kind of relationship it represents (MP7). Students should see by the end of this lesson that equations of the form characterize proportional relationships (for ).
The last activity is optional because it provides an opportunity for additional practice determining whether equations represent proportional relationships, this time without a context to help students focus on the structure of the equations.
- Compare and contrast (orally) equations that do and do not represent proportional relationships.
- Generalize that an equation equivalent to the form $y=kx$ can represent a proportional relationship.
- Use a table to determine whether a given equation represents a proportional relationship, and justify (in writing) the decision.
Let’s develop methods for deciding if a relationship is proportional.
Required Materials
Activity 3
Required Preparation
Calculators can optionally be made available to take the focus off computation.