Using A Grid To Calculate The Area Of An Irregular Figure

Make Connections

Performance Task

Ways of Thinking: Make Connections

  • Take notes about other classmates’ methods for finding the area of Lake Chad.
  • How close is your estimate to that of the rest of the class?
  • If your estimate is larger or smaller, can you explain why? What did you do differently?


As your classmates present, ask questions such as:

  • How did you calculate the area?
  • What strategy did you use to calculate the area in a square that did not completely cover the lake?
  • Why would you use this method to determine the area, as opposed to dividing the figure into composite figures as in the last lesson?
  • Why do you think the problem used the term surface area rather than justarea ?