Walking the Line - Part 2: Students Take the Lead

Traci Seto - Joseph Kerr Middle School

Subject Area - Math (Algebra)
Grade Level - Middle School

Overview: To make the abstract concept of the relationship between motion and slope more concrete, students will connect the everyday, physical activity of walking to a graphing activity.


  • Students will make connections of slope (rate of change) of a line to motion of an object (distance vs time).


  • Set up motion detector, overhead or document camera, and teacher workstation. Review both the hardware set up to students and how the motion sensor works.
  • Review possible student walking conditions:
    1. Start at the CBR (motion sensor) and walk away at a slow steady rate.
    2. Start at the CBR and walk away at a fast steady rate.
    3. Start at opposite end of room and walk towards CBR at slow rate.
    4. Start at the CBR and walk away at a slow steady rate at 3 meters stop for 2 seconds then walk at a faster rate to the end.
    5. Start at the CBR and walk away at a fast steady rate, at 3 meters stop for 2 second then walk at a slow rate to the end.
    6. Start at the CBR and walk away at a fast steady rate turn around at 4 meters and walk back towards CBR at a slow rate.
    7. Start at the CBR and walk away at a slow rate speeding up over the 5-meter walk.
  • Pass out Student Worksheet 2. For each graph, have students describe motions that produce the pictures graphs. Instruct students to make prediction about how to create the four graphs on the worksheet.
  • Call on student volunteers to try to match the graphs.
  • End lesson with whole-class discussion on tying together the concepts of slope and speed: slope

Note: This lesson has been adapted from a workshop by Gail Standiford for CMETS Middle Grades Summer Institute 2002.


  • TI83+ Teacher’s edition with overhead panel and motion detector
  • Computer with TI Graph Link 83+ (optional)

Lesson Resources:



  • Collaborate with peers, experts, and others using telecommunications and collaborative tools to investigate curriculum-related problems, issues, and information, and to develop solutions or products for audiences inside and outside the classroom.
  • Select and use appropriate tools and technology resources to accomplish a variety of tasks and solve problems.

Common Core Standards – Mathematics

  • Grade 7 - Analyze proportional relationships and use them to solve real-world and mathematical problems
  • Grade 8 - Understand the connections between proportional relationships, lines, and linear equations.
  • Algebra I - Create equations that describe numbers or relationships; represent and solve equations and inequalities graphically.

California Content Standards for Mathematics

7th Grade

  • Algebra and Functions 1.5 - Represent quantitative relationships graphically and interpret the meaning of a specific part of a graph in the situation represented by the graph.
  • Algebra and Functions 3.3 - Graph linear functions, noting that the vertical change (change in y-value) per unit of horizontal change (change in x-value) is always the same and know that the ratio (“rise over run”) is called the slope of a graph.

Algebra I

  • Algebra 6.0 – Students graph a linear equation and compute the x- and y- intercepts.