What is Area?

Teacher Lesson Plan

Objectives:

1. To understand that area is measured in square units.
   
2. To learn that the area of a rectangle can be found by counting the number of squares.
   
3. To understand that perimeter is measured in linear units.
   
4. To learn that the perimeter of a rectangle can be found by counting the units around the outside of the figure.

Materials:

(for each group of four students)

1. one bucket of 1 inch square tiles
   
2. one sheet of grid paper - 1 inch size
   
3. four sheets of grid paper - 1 centimeter size
   
4. four pencils
   
5. (optional) colored pencils/pens/crayons
6. Hands-On Math software by Ventura Educational Systems

Classroom Procedure

As a group, using the 1 inch square tiles and the 1 inch size grid paper, build a rectangle with an area of 4 square units.

Some groups may have arranged their tiles to show a 2x2 square. Others may have made a 4x1 rectangle or a 1x4 rectangle. All three of the examples are correct.

On your individal sheet of graph paper, draw the model and label it like this:

Here are nine more problems.

1. Area = 9 square units
2. Area = 10 square units
3. Area = 25 square units
4. Area = 14 square units
5. Area = 36 square units
6. Area = 18 square units
7. Area = 20 square units
8. Area = 2 square units
9. Area = 49 square units

Each student should draw the answer and label A(rea) and P(erimeter) on their individual sheet of graph paper.

Lab Procedure

Open a software program called Hands-On Math by Ventura Educational Systems. Select geoboard and select the tool which displays the area and perimeter window.

Question: Is there a general rule for finding perimeter? Is there a general rule for finding area?

Use the software to test out your ideas. Be prepared to respond in a class discussion.