Question

The top of the cardboard box

measures 9 inches by 4 inches.
How much cardboard is needed
to make the top (only) of the box?
_____inches squared

Answer 1

The quantity of cardboard that is needed to make the top of the box is:

• 36 inches squared.

Explanation:

When the exercise asks you about the "inches squared," it's asking you about the area, the area of a rectangle (a rectangle because a cardboard box regularly is rectangular) is:

• Area of a rectangle = length * width

Now, you must replace the length and the width by the values in the exercise (doesn't matter what is width or length, remember the commutative property of the multiply):

• Area of a rectangle = 9 in * 4 in
• Area of a rectangle = 36 in^2 or 36 inches squared.