Lesson 24

Reasoning with Graphs of Inequalities

These materials, when encountered before Algebra 1, Unit 2, Lesson 24 support success in that lesson.

Lesson Narrative

The mathematical purpose of this lesson is to introduce students to reasoning about points that are solutions to more than one linear inequality. In the associated Algebra 1 lesson, students learn about graphing systems of inequalities and identifying all of the solutions to the system. This lesson supports students to do that work as well as think of points that will occupy regions of the plane bounded by lines. Students also get a chance to keep practicing graphing linear equations, as graphs are available as a tool to support their reasoning, but are not explicitly introduced. Students therefore have a chance to use appropriate tools strategically (MP5).

Learning Goals

Teacher Facing

  • Generate points that are solutions to multiple inequalities simultaneously.
  • Write inequalities described by number puzzles.

Student Facing

  • Let’s solve riddles about inequalities.

Required Preparation

Students may use graphing technology, or graph by hand, for the “Which Side Are You On?” activity.

CCSS Standards

Building Towards