Lesson plan

Lesson 21: From One- to Two-Variable Inequalities

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teaches Common Core State Standards HSA-REI.B.3 http://corestandards.org/Math/Content/HSA/REI/B/3
teaches Common Core State Standards HSA-REI.D.10 http://corestandards.org/Math/Content/HSA/REI/D/10
teaches Common Core State Standards MP8 http://corestandards.org/Math/Practice/MP8
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In this lesson, students begin the move from one-variable inequalities to two-variable inequalities. They plot points on a coordinate plane that fit a one-variable inequality to see how that divides the plane. Then, students select points that are on, above, or below a line that represents a given equation. In the associated Algebra 1 lesson, students draw the graph that represents solutions to two-variable inequalities. The work of this lesson supports that learning by providing some additional work that builds on their current understanding of one-variable inequalities and linear equations.

Students look for regularity in repeated reasoning (MP8) when they use the points selected by the class that satisfy a one-variable inequality to determine the region of the plane that represents the solution in two dimensions.

Lesson overview

  • 21.1 Warm-up: Describing Regions of the Plane (5 minutes)
  • 21.2 Activity: More or Less (20 minutes)
  • 21.3 Activity: Above or Below the Line (15 minutes)

Learning goals:

  • Draw the solutions to one-variable inequalities on a coordinate plane.
  • Write points that are on, above, or below a line represented by a given equation.

Learning goals (student facing):

  • Let’s look at inequalities in two dimensions.

Standards:

  • This lesson builds towards the standard: CCSS.HSA-REI.D.12MS.A-REI.12MO.A1.REI.C.7MO.A1.REI.C.8

 

 

 

 

 

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