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Lesson

7th Grade Math - Area and Perimeter

Clip 2/11: Introduction

Overview

In this problem, we engage our students in a consideration of how others might have approached the Pizza Crusts problem, probing them to identify the misconceptions about perimeter and area.

Teacher Commentary

In this problem, we engage our students in a consideration of how others might have approached the Pizza Crusts problem, probing them to identify the misconceptions about perimeter and area. At the beginning of the class session, Patty Ferrant and I were trying to invoke what students knew about area and perimeter, focusing mainly on what was causing them problems whenever they dealt with the concepts. In the introduction, I feel it's important to not let kids know it's the introduction, being subtle about the content. Our goal was to set an invitational tone parallel with the task. This lent itself nicely to the MARS task, because the first problem is so accessible. We wanted every student to have access to the task and to give us some information about area and perimeter.

The students in this course, while not my own students, are similar to 7th grade students that I have taught. Patty and I teach in the same city, so the student populations are similar. They also share conceptual challenges--struggling with geometry in 7th grade. Many students had not been exposed to geometry in a hands-on way and were unable to understand the challenges with finding either perimeter or area when a constraint was imposed on the other.