A Simple, Quick Activity to Make Area, Perimeter, and Volume “Click” with Kids
Every year the same thing happens. Students get area, perimeter, and volume confused. Several years ago I went to an NCTM conference and a presenter there suggested this activity. I kind of made it my own since I have been teaching fifth grade a lot lately. She suggested taking index cards and labeling them “AREA” and “PERIMETER”. I added “VOLUME” also. Then read aloud several statements and have students hold up the card so that all including you can see. I had a list of about fifteen statements such as:
- How much sand to fill up a sandbox?
- How far is the distance around the playground?
- How much bulletin board border do you need to go around the bulletin board?
- How much paint do we need to cover the classroom wall?
- How much fabric do you need to make a tablecloth to cover the table?
- How much water is needed to fill a swimming pool?
- How much carpet do I need to buy to make a comfortable reading center?
We did this orally in class for about fifteen minutes and after each statement, I asked the student why the answer was what they held up on his or her card. Sometimes instead of asking why the answer is perimeter, I asked why is the answer not area or volume. At first when we did this activity students had mixed answers and I could tell that they didn’t have an understanding of these terms. After spending a while explaining why or why not an answer was correct, I noticed that most of the students were correct as they held up their cards. I had thought of giving the students three different colored cards so that I could easily tell which word they were holding up, and then I changed my mind. I decided that if I could quickly tell which card that students were holding up, then other students would simply look at the color of the “smart” kids’ cards and not do much of their own thinking.
To extend this activity, I had students keep their cards in their notebooks and add to them the next day. On the back of the perimeter card, students wrote “UNITS”. On the back of the area card, students wrote ” SQUARE UNITS”, and on the back of the volume card, students wrote “CUBIC UNITS”. I used the same fifteen statements and had the students hold up the cards just as before, but this time with the units side facing me. Doing this helped them see the connection between perimeter, area, and volume with which type of units each measured.
After these activities most students were holding up the correct card and had the general understanding that:
- perimeter and units measure distance
- area and square units cover
- volume and cubic units fill.
This activity could be used in other disciplines as well if students are struggling with the meaning of a few terms. The beauty of this is you as a teacher have an immediate quick assessment for students who aren’t understanding as soon as you see their card.