1
$\begingroup$

I'm trying to convert 20.7x10^(-4)m^2 to inches^2. And after that's done use it to figure the price at 3.25/lb^2. The answer is supposed to be $10.43. I have the conversion factor 1m = 39.37in. I've tried 20.7x10^(-4) x 39.37, then that times the 3.25. I tried converting that to inches, cubing it and then x 3.25, and a couple other things. I know I've done this before but I can't kind the scrap sheet I did it on and can't figure out what I did here last time.

$\endgroup$
2
$\begingroup$

To convert from square metres to square inches, we multiply by $(39.37)^2$.

An example with simpler numbers may help. Recall that a foot is $12$ inches. A $1$ foot by $1$ foot cardboard square can be divided into $144$ $1$ inch by $1$ inch squares, so it has area $(12)^2$ square inches. Thus $1$ square foot is $(12)^2$ square inches.

| cite | improve this answer | |
$\endgroup$
  • $\begingroup$ Wow have I been over thinking that. Thanks... $\endgroup$ – windy401 Sep 6 '14 at 0:54
  • $\begingroup$ You are welcome. You will find that when you calculate using $(39.37)^2$, you will get about $10.4276$, which, rounded to two decimal places, is the answer you are looking for. $\endgroup$ – André Nicolas Sep 6 '14 at 0:57
1
$\begingroup$

You have to do the following:

$$x=20.7\cdot10^{-4}\text{m}^2=\Big(\frac{39.37 \text{ in}}{1 \text{ m}}\Big)^2$$

That's equal to :

$$x=20.7\cdot10^{-4}\text{m}^2=\frac{39.37^2 \text{ in}^2}{1 \text{ m}^2}$$

The meter squared just cancel and you get:

$$x=20.7\cdot10^{-4}\cdot 39.37^2 \text{ in}^2$$

I recommend this method in order to do unit conversion.

| cite | improve this answer | |
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.