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7th Grade Math - Area and Perimeter

Clip 8/11: Problem 3 - Area & Perimeter


Our next goal in the lesson is to have students take what they had learned in the previous discussions and apply it to the core problem.

Teacher Commentary

We took this problem from MARS, which was the second to the last problem of the task. We asked students to come up with different sized rectangular pizzas that had an area of 36. We wanted them to justify their work based on an imposed condition. This was not where we wanted to end originally, but this ended up being the last problem in the time given. Later, Patty finished the lesson with the last problem on the MARS task with the same students the following day. Here, students solved the problem on paper (the previous problems having been a discussion). We wanted them to work with each other, using manipulatives if desired. Their work would be collected so that we could assess growth from actual student work. We wanted to see if students had a better understanding of the differences of area and perimeter, thus clarifying their previous misconceptions. Additionally, we also hoped that students would be better at reasoning and justifying their thinking through visual models and verbal explanations. During this clip, you will see Patty and me walk around and ask students "Where does your answer come from?", "Can you show us?", "Can you prove it on your paper?", etc.