This lesson kind of came to me last year in the middle of teaching area and perimeter, so I made one of those last minute changes to the lesson plan that we are all so familiar with. It went well, but I knew if I really planned with this idea in mind, it would be much better. So this year, when we got there, I made an actual lesson plan around the spur-of-the-moment idea I had last year. I am super excited about how well this lesson went, so I wanted to share it with you!
Students worked in groups of 3-4, rotating through the 5 shapes. First, I asked them to figure out the perimeter of their shape. Most of them did this pretty easily by counting the edges of the tiles around the shape. Then, I asked them to write an equation to show the perimeter. Most of them figured out immediately to add up the four sides. The only groups who had trouble were the two with squares, so I worked with them until they had it.
Then I asked them to find the area, which they again did by counting the tiles in the middle of the shape - exactly as I expected. Then, we worked together to figure out that they could multiply the length x width to get the area. There were a few skeptics in the room who wouldn't believe it always worked until they tried all of the shapes. I loved it!
I had a "Challenge" shape taped off too, but we ran out of time, so we will be working on it tomorrow. Hopefully, we will be able to figure out how to find the area of this shape on their own with the knowledge we have built today!
I whipped up a quick answer sheet for students to show their thinking as they traveled to the different shapes. You can grab a free copy by clicking the photo below!
That's it for today. How do you teach area and perimeter?