hi
excel see a percent as a decimal of 1. so excel see 31.7% as .317.
=211.9*(1-.317)
or 144.7 which is 68.3 % or .683(1-.317) of 211.9.
if 211.9 was in B2 and 31.7% was in c2 then the formula could look like this.
=B2*(1-C2)
c3 would be enter as .317 then formated to percent to look like 31.7%
formating does not change the value, it only changes the way it looks.

regards
FSt1

"Serena" wrote:

I have been working as an Elementary computer teacher. I was recently
promoted to teaching MS/HS... I have been busy this summer creating lesson
plans and I have more to learn about Excel & formulas. I want to teach the
students how to use a particular chart. I have the top 10 countries that
import from the U.S. I have the $ amounts for each country. Canada imported
211.9 billion in 2005, which is up 31.7% from 2002. What is the formula to
figure out the amount in 2002? I know that on the news I will hear that a
certain stock is up _______ % from yesterday. I could forego this, but
believe that this is very important to teach. Algebra was NOT my strong
suit. My husband came up with a formula, but neither of us know how to write
it into Excel. I need to understand it, so that I can teach it. Your help
is greatly appreciated!
-Serena-