Using square units is a great way to introduce the concepts of area and perimeter.

1. Square units help make sense of the processes used to find perimeter and area by offering visual representation.
2. Square units give students something they can easily count.

To find the area of a shape, just count the number of unit squares used to create the shape.
To find the perimeter, count how many unit jumps are needed to make your way around the shape.

Example:
1.) Find the area and perimeter of the following shape:

AREA: In this shape, there are 15 unit squares, so the area is 15 square units.

PERIMETER: To find the perimeter, start in the upper left-hand corner.
To travel across the top of the shape, you would need to make 5 unit jumps. To travel down the right side of the shape, you would need to make 3 unit jumps. To travel across the bottom of the shape, you would need to make an additional 5 unit jumps. And finally, you would need to make an additional 3 unit jumps to travel up the left side of the shape, back to where you started.

The perimeter is the sum of all your unit jumps: 5 units + 3 units + 5 units + 3 units = 16 units.

NOTE: In the worksheets below, if a square is not shaded, don’t include it in the area. If the center of the shape is missing, that won’t change the perimeter. The perimeter is always the distance around the shape, whether the inside is there or not.