Defining Regions Using Inequalities

A little background

  • In case you are trying the MARS MAP Classroom Challenges for the first time, it is recommended that you read the Brief Guide for teachers and administrators before you get started.
  • Before the lesson, students work individually on an assessment task that is designed to reveal their current levels of understanding and difficulties. You then review their work and create questions for students to answer in order to improve their solutions.
  • After a whole-class introduction students work collaboratively, in pairs, on a game. One student decides on the position of a 'target point' on a coordinate grid and gives clues in the form of algebraic inequalities (e.g. 3y + 2x < 12). The other student uses these clues to find the location of the target point. There is a strategic element to the game: what are the best clues to give, so that the target may be found quickly?
  • In a whole-class discussion students review the main math concepts of the lesson.
  • Students return to their original assessment tasks, and try to improve their own responses.
  • Additional resources for this lesson include: defining_regions_inequalities_slide_beta.ppt


  • To help you assess how well students are able to use linear inequalities to create a set of solutions.
  • To help you identify and assist students who have difficulties in representing a constraint by shading the correct side of the inequality line.
  • To help you identify and assist students who have difficulties in understanding how combining inequalities affects a solution space.
70 mins K-12.MP.1 HSA.REI.D.10 HSA.REI.D.12
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