Rectangle area by multiplying
Multiply side lengths to find areas of rectangles and represent whole-number products as rectangular areas
What a learner can do afterwards
- Calculate the area of a 7 cm × 9 cm rectangle as 63 cm²
- Draw a rectangle with area 36 square units and label its side lengths
- Solve: A garden is 8 m by 5 m — what is its area?
The lesson
You already know how to find area by counting unit squares one at a time. There is a faster way. If you know the length and the width of a rectangle, you can multiply them to get the area right away.
A rectangle is 7 cm by 9 cm. Multiply the side lengths: 7 × 9 = 63. The area is 63 square centimeters, written as 63 cm².
Always write the unit name after the number, like cm² or m². The small 2 means the squares fit inside the shape, not just a length measured across.
To find area, multiply the two side lengths and label the answer in square units, like cm² or m².
Watch it
Where it sits
Where this leads
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.