Lesson Plan: Types of Slope

Lesson Objectives

• Identify and distinguish between positive, negative, zero, and undefined slopes
• Interpret the meaning of different slope types in real-world contexts
• Recognize slope types from graphs and equations

Florida BEST Standards

• MA.8.AR.2.1: Given a table, graph or written description of a linear relationship, determine the slope.
• MA.912.AR.2.4: Given a table, graph or written description of a linear function, determine the slope and interpret it as a rate of change in real-world situations.

Prerequisite Skills

• Familiarity with the coordinate plane and plotting points
• Understanding of the concept of slope as the ratio of the vertical change (rise) to the horizontal change (run) between two points
• Experience with using interactive graphing tools or online resources (a Desmos activity is provided in this lesson)

Engage (5 minutes)

1. Use these math clip art pieces to show different types of slopes: https://www.media4math.com/library/75389/asset-preview
2. Ask students to observe the directions of the lines and describe what they notice about the slopes.
3. Encourage students to share their observations and discuss the differences in line directions.

Explore (15 minutes)

1. Play the following video, which describes the different types of slopes: https://www.media4math.com/library/75390/asset-preview
2. Review the following vocabulary terms:
   • Positive Slope: https://www.media4math.com/library/42968/asset-preview
   • Negative Slope: https://www.media4math.com/library/42969/asset-preview
   • Zero Slope: https://www.media4math.com/library/42970/asset-preview
   • Undefined Slope: https://www.media4math.com/library/42970/asset-preview
3. Have students use this Desmos activity: https://www.media4math.com/library/75388/asset-preview. Students can change the slope of the line in two ways:
   • Clicking and dragging on one of the points
   • Changing the values for a, b, c, and d to modify the coordinates.
4. Have students use the Desmos activity to show examples of these types of slopes:
   • Positive Slope
   • Negative Slope
   • Zero Slope
   • Undefined Slope

Evaluate (10 minutes)

1. Facilitate a class discussion by asking students to share their observations and findings from the previous activity.
2. Address any misconceptions or clarify any confusions that may arise.
3. Provide individual practice problems or a short quiz to reinforce the concepts of positive, negative, zero, and undefined slopes.

Quiz

1. What type of slope does a line have if it is slanting upwards from left to right?
   A. Positive slope
   B. Negative slope
   C. Zero slope
   D. Undefined slope
   
    
2. If a line is horizontal, what is its slope?
   A. Positive slope
   B. Negative slope
   C. Zero slope
   D. Undefined slope
   
    
3. A vertical line has what type of slope?
   A. Positive slope
   B. Negative slope
   C. Zero slope
   D. Undefined slope
   
    
4. Which type of slope would a line have if it is slanting downwards from left to right?
   A. Positive slope
   B. Negative slope
   C. Zero slope
   D. Undefined slope
   
    
5. If the slope of a line is 0, what can you say about its direction?
   A. It is slanting upwards
   B. It is slanting downwards
   C. It is a horizontal line
   D. It is a vertical line
   
    

Answers Key

1. A

2. C

3. D

4. B

5. C

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