Area and Perimeter Floor Plan Lesson SB file (This SB file will be used throughout the entire lesson.)
I opened up the SB file to the first page and left it there for them to read as I wrote a title "Area and Perimeter" on the whiteboard next to the SB. I asked them to silently think about each of the professions listed on the SB page, and jot down a few of their ideas in their math notebook. I gave them a few minutes and then asked them if they remembered what area and perimeter were? Several students offered up answers that were correct and accurate which told me that they had understood 3.MD.C.5 and 6 from last year.
We talked about each profession listed and many of my students didn't know what a mason was, so they looked it up on their iPads. We discussed how using area and perimeter could be part of each of the jobs listed. I then asked them where they had seen their parents use area and perimeter?
A few of my students talked about new carpeting. One said that a man had come over to measure the room and went around two walls. The other student said that their dad was looking at carpeting and kept talking about how many square feet the room was and that it would be more expensive to put down hardwood floors right now. Another student piped up and said something about windows, but it turned out she was really talking about perimeter, so it was a good segue for me to compare the two.
I wrote the formulas for area and perimeter on the board and explained each one. Then I drew an area diagram while talking about the carpeting situation, and asked them which, area or perimeter, would be the correct calculation to carpet the room?
One student volunteered to write the correct formula under my area drawing. He explained that you had to multiply to find "all the area that the rug was in," that it "covered the whole floor."
I drew the other student's window that she talked about, and explained that the carpenter was cutting a hole in the wall for the new window and needed the exact measurements around the window to do it correctly. Otherwise, they might get the window turned around the wrong way.
We talked about how the word "around" would be a good clue word to remember perimeter.
I turned to the second page of the SB file and we looked at the floorplan drawing together. I asked them what units the floor plan was drawn in? They knew right away that it was in feet. I explained that the measurements are written a little strangely and that the dash stood for inches. So the master bedroom was 15 feet 1 inch by 10 feet four inches. I am not sure why this plan is notated like that. I asked them if they knew what unit of measurement we would use if this was a floor plan from Europe or Australia? One student said "Meters!"
I held up 2 meter sticks and told them that we were going to measure our classroom's length and width. It is a tricky classroom because it isn't a quadrilateral. So, I asked them where they thought we could get a length and width? One boy pointed out the squared corners and we decided together to work from opposite sides of the room. Hands on measurement of classroom.
Students had fun counting the meter stick and coming up with 13 x 12 meters. I asked if they thought this measurement would be an accurate one? I had several responses. Two students realized that we were leaving out the triangular section near my desk and that the SB wall was on an angle. One student thought it would be accurate, while another talked about how we were measuring in the middle of the room, not near the wall. Another talked about how when we flip the meter stick, we probably lost or gained some centimeters. I was pleased to hear such critical thought!
After we measured the classroom, I asked all students to calculate the area and perimeter as if the room were a quadrilateral figure and use the formulas to calculate. When we were finished, I asked students for their calculations. For the most part, they had used the formulas correctly, accurately multiplied using area model and could share the answers in square meters or meters.
I turned to the third page of the SB file and we went through the thoughts and questions. As we went, I explained that if we could design a floor plan that fit just our needs and interests, that it would really make houses interesting. I explained that my house would have a room for my piano; a room for sewing, writing, and reading; a huge kitchen, etc., all relating to my interests.
I asked for students to share some of their interests that they could use a room for?
One student talked about his dad's model trains and that they took up the whole basement. Another student talked about having a big bedroom with their own bathroom. He would give his sister a little bedroom. I asked if they thought a movie theater room would be fun to have since we are so interested in movies and watching things on TV. They all agreed.
I turned to the next page and explained our task. I went through that page, step by step, pausing for questions. None arose. I could tell that they needed an example drawing. I showed them a sample drawing I had sketched on the graph paper. We talked about how I expected that the floor plan rooms share walls and that measurements would be realistic. I explained that room sizes are usually like our classroom size or smaller. In other words, I didn't want to see a room 300 meters long! They thought that was pretty funny. I told them that they could draw a garage separately if they preferred. This Floorplan drawing is a student's. It is much better than my example!
I handed out graph paper with 1/4" squares and asked them to list the rooms they would like to draw. I explained that it was important to be accurate and showed an example drawing on a piece of graph paper. I showed them how linear meters should be labeled and we agreed once again that our floor plans should be labeled in meters.
I paused for questions. One student asked a question about the formulas and if they had to show their work. Because the standard says that they need to use the formulas, I told them that the work shown proves to me that they have mastered the standard.
I stopped students after I could see that their plans were started. I emphasized that they needed to remember to take their notes home so they could use the formulas to figure out area and perimeter easily. I also emailed directions by sending them the SB pdf file for directions. Area and Perimeter Floor Plan Lesson
We closed our lesson by quickly reviewing the formulas and the directions on the SB file. To support the "why" of this assignment, I asked students to explain what the purpose of figuring out area would be for their floor plan? We listed, carpeting, understanding living space, flooring etc. Then we talked about perimeter. We discussed that perimeter would be needed to figure out how to trim the floor area, ( I showed them the base shoe in our classroom) and we talked about wall paper borders.