In RS2 Level C, Lesson 109, the child is introduced to measuring area. After a problem of square inches is discussed, the lesson shows the child how to write 12 square inches: 12 in². Then, there’s an explanation on the side that reads:

*Be sure to read *12 in²* as “twelve square inches.” Avoid saying “twelve inches squared,” which has an entirely different meaning.*

**Kirsten** sent us an email and wanted a more complete explanation of the different meaning of twelve inches squared. Good question, Kirsten!

Ok. I will confess I had to go to Dr. Cotter to clarify this for both of us! So here it is.

First, if you say “12 inches,” that’s easy. It’s just 12 inches!

It’s a measurement of area, indicated by the word “square” and the little ². The measurement for the area under discussion is inches. Hence the name “12 square inches,” written by “12 in².”

# 12² = 144

Extending that, if you say “12 inches squared,” it’s a logical process to square 12 inches, giving us 144 inches.

So “12 inches squared” is a long distance of 144 inches and “12 square inches” is a 3 by 4 inch area. Or 2 by 6. Or 1 by 12. You get my drift.

12 inches squared is 12 inches times 12 inches which makes 144 square inches.

My question is Calvin’s blank art canvas measures 27 inches by 9 inches. which number sentence shows how many square inches he has available to paint?

27 + 9

27-9

27*9

27/9

Hi, Theresa.

The answer would be 27 x 9. He would have 243 square inches available to paint.

My question is

Find the area of the 12 inch square..(the answer will be in squar inches) what is the correct formula for that?

Hi, Joscelym.

The term ’12 square inches’ is referring to area. Area is calculated by the formula b x h (base times height).

The term ’12 inches squared’ is referring to a calculation being made. When you square something, you are multiplying the same number two times. In the case of 12 inches squared, you will be calculating 12 inches x 12 inches. This would not be referring to area, but suggesting that a calculation is to be made. Think of it without the term ‘inches’. Twelve squared would be 12 x 12. The term inches is just informing you that the 12 is a measurement.

I hope that helps! If you have any further questions, please feel free to post them here or email RightStart Math directly at info@rightstartmath.com.