Comparing Lines and Linear Equations

Mathematical goals

This lesson unit is intended to help you assess how well students are able to:

  • Interpret speed as the slope of a linear graph.
  • Translate between the equation of a line and its graphical representation.


  • Before the lesson, students work individually on an assessment task that is designed to reveal their current understanding and difficulties. You then review their work and create questions for students to answer in order to improve their solutions.
  • During the lesson, students work in small groups on a collaborative task, matching graphs, equations, and pictures. At the end of the lesson there is a whole-class discussion.
  • In a follow-up lesson, students review their initial solutions and then use what they have learned to either revise the same introductory assessment task or complete a different task.

Materials required

  • Each student will need copies of the assessment tasks, The Race and The Walk-a-thon. It will help students if the two pages of each task are printed on separate pages.
  • Each small group of students will need a mini-whiteboard, pen, and eraser, the cut up Card Set: Graphs 1, Graphs 2, Equations, Flowing Liquid, a large sheet of paper for making a poster, and a glue stick.
  • If possible, a real model of two identical containers connected at the neck to demonstrate the liquid flow. For example, two identical soda bottles, connected at the neck with tape.
  • There is a projector resource to support whole-class discussions.

Time needed

Approximately 20 minutes before the lesson, an 80-minute lesson (or two shorter lessons), and 20 minutes in a follow-up lesson. Exact timings will depend on the needs of the class.