I've always loved teaching geometry! It's a strand of math that allows students to use different types of mathematical thinking, and gives them a break from the number crunching calculations that are heavily emphasized in other strands. Geometry is more "visual", and gives students a chance to think of their world in a whole new way.
However, certain geometrical techniques do require some number crunching. Calculating area and perimeter are two examples. Luckily, once the techniques are learned, the calculations required to find area and perimeter are quite simple. One way that I like to introduce this concept is by using my tried and tested "Estimation Game". This game can be used for both perimeter and area. The first example will focus on perimeter.
First, you must define what perimeter is. It is a measurement of the distance around the outside of a shape. It's important that students realize that the unit of measurement can range from inches to miles - it depends on the size of the shape you are measuring. I tell students that we're going to figure out the perimeter of our whiteboard, and I have them decide which unit of measurement would be the most suitable to use. Feet, of course! In the middle of the whiteboard I draw a box, and I go around the room asking each student to guess how many feet it is around the perimeter of the whiteboard. I put their initials next to their guess. If someone makes a guess that's already in the box, I put a dot next to the number, and add their initials to it. After everyone has guessed, I break out my yardstick and measure the perimeter. Whichever student, or students, comes the closest may get some sort of prize, like a new pencil, or a Hershey's Kiss.
This game can also be used to determine area, which is the number of square units inside a shape. Again, the students must realize that the unit of measurement depends on the size of the shape you're measuring. The next day, we play the Estimation Game again. This time students must guess what the area of the whiteboard is. We determine that, once again, feet are the best unit of measurement to use. Before this game starts, I draw a one foot square box inside the whiteboard to illustrate what they are trying to visualize, but I erase it before the guessing begins! We play the game the same way. After everyone has guessed, I ask the students how we are going to figure out how many of the one foot square boxes will fit inside the whiteboard. Do we have to draw a bunch of boxes and count them up? There must be a better way! Eventually, I lead them to the classic formula - Area = Length X Width. We go back to the prior day's game on perimeter, and I write down the length of the whiteboard and the width. We multiply them and, viola! We have calculated the area.
This simple game introduces the concepts of perimeter and area in a way that is fun for students, and leads to total understanding for virtually everyone in the class. As the year goes on, you can play the game to determine the perimeter and area of larger spaces - like the perimeter and area of the classroom itself, the playground, even the entire campus. Here are some other lesson plans about area and perimeter that I think you'll enjoy.
Area and Perimeter Activities and Lessons:
Students explore the relationship between area and perimeter by building cyberspace ships. This multi-media lesson uses a video clip and a website from the show "Cyberspace". The links are provided in the lesson. After viewing the video clip, students access the website which challenges them to build spaceships with different areas and perimeters. This is an ambitious lesson, which requires a lot of prep, but it should be worth the effort.
What better way to explore area and perimeter than by planning a school garden? This wonderful lesson requires students to determine the measurements of the garden, research the types of plants that would be suitable, and challenges them to formally present their plan to the principal. Math, science, and language arts - all in one lesson!
This inquiry and technology-based lesson allows students to solve a real life application of area and perimeter. They use geoboards, take an on-line quiz, and work in cooperative groups to create a Powerpoint presentation on area and perimeter. This excellent lesson uses exciting and innovative ways to reinforce the concepts of area and perimeter.
This upper-elementary lesson requires students to find the area and perimeter of non-traditional shapes. Students utilize pentomino pieces to design and construct their islands. Students must write an essay explaining how they were able to calculate the area and perimeter of their island, and must decorate their islands using color and depicting landforms. Another great cross-curricular lesson!
What activities do you do with students to teach them about area and perimeter?