SWBAT compare and contrast area and perimeter.

Area and perimeter are related concepts which are difficult for students to distinguish.

This lesson is intended to help correct the many student misconceptions about area and perimeter. My students have these concepts and formulas all mixed up together. This lesson helps them recognize that while the two are related there are some important differences. Comparing and contrasting with a Venn diagram helps them understand when it is appropriate to use which tool. (mp5)

15 minutes

The warm up (Which Would You Use? Area or Perimeter) asks students to explain how they decided to use area or perimeter in order to answer the last problem from their homework last night. They are told to take out the "shutters" they made in the previous lesson (Making Shutters) and see if they can find any useful information to help them explain.

30 minutes

Students are given a copy of a Venn Diagram to help them compare and contrast differences and similarities between area and perimeter. They are encouraged to use each section of their "shutters" to help them think about it. Small groups share ideas which are recorded on a whole class Venn Diagram. Included on the Venn diagram are scenarios which would give rise to area or perimeter calculations.

Students then complete the "shutters" they made in the previous lesson (Making Shutters) by creating their own graphic representation of both area and perimeter on the front flaps.

9 minutes

Students revisit two problems from the homework (5 & 6) and are asked to create a contextual problem for each (see: Write a story problem area perimeter) One problem asked for the area and the other asked for perimeter. Students are then asked to share their problems in their math family group. The groups are asked to make sure that the scenarios or stories would give rise to area or perimeter calculations in the original non contextual problems.

Homework consists of writing arguments for or against a set of statements. I give several scenarios in which I have calculated area and perimeter. Some of my calculations may be correct, some may be incorrect, or I may calculate area when I should calculate perimeter.

Homework