What is Area?
Teacher Lesson Plan
- To understand that area is measured in square units.
- To learn that the area of a rectangle can be found
by counting the number of squares.
- To understand that perimeter is measured in linear units.
- To learn that the perimeter of a rectangle can be
found by counting the units around the outside of the
(for each group of four students)
- one bucket of 1 inch square tiles
- one sheet of grid paper - 1 inch size
- four sheets of grid paper - 1 centimeter size
- four pencils
- (optional) colored pencils/pens/crayons
- Hands-On Math software by Ventura Educational Systems
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.
One student should model the problem using the tiles and the 1 inch grid paper. (Take turns being the person to make the rectangle using the squares) .
- Area = 9 square units
- Area = 10 square units
- Area = 25 square units
- Area = 14 square units
- Area = 36 square units
- Area = 18 square units
- Area = 20 square units
- Area = 2 square units
- Area = 49 square units
Each student should draw the answer and label A(rea) and P(erimeter) on their individual sheet of graph paper.
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.