Graphing Inequalities

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Objective

SWBAT graph inequalities on a coordinate grid.

Big Idea

What is the difference between graphing on a number line and on a coordinate grid?

Launch

5 minutes
  • POD

As student enter the room, they will have a seat, take out their Problem of the Day (POD) sheet and begin to work on the question on the SMARTboard. The POD also allows students to use MP 3 continually based on the discussions we have about the problem each day.

POD:  Solve the inequality then graph the solution.

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This POD question is a review of the work we have done with solving inequalities. As we review the answer to the question, I can touch base with students on any concepts they may not grasp about finding the solution.

  • Learning Target

The target for the day is also on the SMARTboard each day when students enter the room.  The target for today’s lesson is SWBAT to graph solutions to inequalities on a coordinate grid.

Explore

30 minutes

As an activity today, students will complete the sheet, Inequalities, to introduce the concept of graphing an inequality on a coordinate plane. We will do the first problem together, as a class, walking through the steps as a review. We will review the parts of a coordinate grid and plotting points on the grid. We will also review how to use the table to organize the values for the graph. After the first problem, students will work through the rest of the sheet individually. When the class has finished, we will demonstrate each problem on the board and discuss the steps to solve and the outcome of each one. How do students know where to shade the answer? In which quadrants do the answer sets belong? How do we classify points that do not fall in the shaded areas?

My students are sometimes challenged by the concept of graphing on the coordinate grid. Conceptually, they have trouble remembering which coordinate is x and which is y. With practice, they are usually able to graph points and indicate the inequality set. It does take practice. If today's lesson is treated as an introductory lesson, we may follow up with another activity just to allow them additional practice.

Landing

5 minutes

The exit ticket prompt today is designed to get an understanding of what students think and know about graphing an inequality. It will also tell me what we may need to focus on in subsequent lessons-what they need additional support on.

PROMPT: How does the graph of an inequality on a number line differ from the graph of an inequality on a coordinate grid?