## steve816 one year ago Please help me! The volume of a block of wood equals 78 cm^3 What is its volume in cubic inches?

1. anonymous

2.54cm / inch 78cm^3*(1 inch/2.54cm)^3 The cm cancel out =78/(2.54^3)

2. steve816

I don't think that is right...

3. anonymous

Stoichiometry has a fancy name but it's very easy. Just like $\frac{ 1 }{ 2 }*\frac{3}{3} = \frac{3}{6}$ You are multiplying your value by 1, because the value of numerator equals the denominator. And just keep doing it so units cancel out to the ones you want to result to. 2.54 cm = 1 inch and you keep canceling the cm until you get in^3 (and not 1/in^3)

4. anonymous

$78cm^3\frac{ 1 inch }{ 2.54cm }\frac{1 inch}{2.54cm}\frac{1inch}{2.54cm}$

5. anonymous

It's correct. If you have cm in the numerator and multiply it by something that has cm in the denominator, the cms cancel out.

6. anonymous

Thanks kestry, it's tough entering fractions on a phone

7. steve816

Thanks everyone for the help :) I think I understand it now!

8. anonymous

Haha, you answered the question so fast and well!

9. anonymous

Woo, thanks steve! Good luck on the rest of your hw

10. steve816

Thanks kestry! By the way, what are you working on kestry?

11. anonymous

I'm working on Calculus /cry