3rd Grade Math · Area of Rectangles
Count unit squares Worksheets
Fresh practice, ready to print. Answer key included.
Rectangles covered in unit squares. Count them to find the area.
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Or start with a ready-made version.
How it works: a quick refresher
The rules this worksheet practices, then one problem worked from start to finish.
| Strategy | How it works |
|---|---|
| Area is the space inside | Area is measured in square units: the number of unit squares that cover the shape. |
| Multiply length by width | A rectangle 6 cm long and 4 cm wide has an area of 6 × 4 = 24 sq cm. |
| Rows of squares | 6 × 4 means 4 rows of 6 squares, the same as counting every square. |
| Missing side | If the area is 24 sq cm and one side is 6 cm, the other side is 24 ÷ 6 = 4 cm. |
| Split and add | Split an L-shaped figure into two rectangles. Find each area, then add. |
Worked example
An L-shaped figure is 8 m long and 6 m tall, with a 3 m by 2 m corner cut out. Find its area.
- 1Think of the whole rectangle first: 8 × 6 = 48 sq m.
- 2The missing corner is 3 × 2 = 6 sq m.
- 3Take the corner away: 48 − 6 = 42 sq m.
- 4Check by splitting into two rectangles and adding their areas. You get 42 sq m again.
Ready-made versions
Three fixed versions you can link to or share. Each is a PDF with its own answer key.
- Count unit squares Worksheets, version 1Worksheet PDFAnswer key PDF
- Count unit squares Worksheets, version 2Worksheet PDFAnswer key PDF
- Count unit squares Worksheets, version 3Worksheet PDFAnswer key PDF
Grade level and standard
Written for 3rd grade math (measurement) and aligned to CCSS 3.MD.C.7. It also works as review in later grades.
Common questions
- Is there an answer key?
- Yes. Every worksheet has a matching answer key with each answer worked on the same grid or layout as the question. The worksheet code printed at the bottom of each page pairs a sheet with its key.
- What is the difference between area and perimeter?
- Area is the space inside a shape, counted in square units. Perimeter is the distance around the outside, counted in plain units such as cm. A 6 cm by 4 cm rectangle has an area of 24 sq cm and a perimeter of 20 cm.
- Are the figures drawn to scale?
- They are drawn in proportion, but always use the numbers on the sides, not a ruler.
- How many different versions are there?
- About a million per skill. Each time you press the button the problems are generated fresh, so you can print a different version for every student, a retake, or another night of practice.
- Are the worksheets free?
- Yes. They are free to print and copy for your home or classroom, with no sign-up.
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