
Algebra PreAlgebra and Basic Algebra Math Forum 
 LinkBack  Thread Tools  Display Modes 
July 29th, 2011, 09:52 AM  #1 
Joined: Jul 2011 Posts: 1 Thanks: 0  Calculate x as a % of y?
Hi, can anyone tell me how to calculate x as a % of y? For example What % is 31 million of 72 million, for example? Thanks guys, sorry if this sounds dumb! I'm learning! Z 
July 29th, 2011, 01:06 PM  #2 
Joined: Jul 2011 Posts: 227 Thanks: 0  Re: Calculate x as a % of y?
What's 1% of 72 million?...

July 29th, 2011, 08:13 PM  #3 
Global Moderator Joined: Jul 2010 From: St. Augustine, FL., U.S.A.'s oldest city Posts: 11,618 Thanks: 145 Math Focus: The calculus  Re: Calculate x as a % of y?
I would rewrite the question as follows: What percentage of y is x? Then translate the question into an equation as follows: "What" is z (the unknown) "percentage" is /100 "of" is · (multiplication) "y" is y "is" is = ("is" is short for "is equal to") "x" is x Now, putting it together, we have: (z/100)·y = x Solve for z by multiplying both sides by 100/y z = 100·(x/y) So we see that when we want to know what percentage x is of y, we simply divide x by y then multiply by 100. 
July 30th, 2011, 08:12 AM  #4 
Joined: Jul 2011 Posts: 245 Thanks: 0  Re: Calculate x as a % of y?
You could also think: Percentage is actually an 'operator'. . . I didn't realize this (I was very lackadaisical in my intuitive side of math. . .) until a while back. Basically, a percentage sign means: This is because of the equality: Interestingly enough, it turns out that percentage islike all mathematical operatorsa convention of sorts to simplify an expression. I think that's pretty coolthe entire world uses a mathematical operator without necessarily knowing what it means. xD 
July 30th, 2011, 10:19 AM  #5 
Global Moderator Joined: Oct 2008 From: London, Ontario, Canada  The Forest City Posts: 5,792 Thanks: 124  Re: Calculate x as a % of y?
31/72 ? .4305 ? 43.05%.

July 30th, 2011, 08:11 PM  #6 
Joined: Apr 2011 From: USA Posts: 782 Thanks: 1  Re: Calculate x as a % of y?
I look at this in a much different manner. I find most people don't have too much trouble learning how to find x% of some other number, which is just a multiplication. i.e. what is 10% of 2100: 2100 * .10 = 210. (And refer to CherryPi's post about why you're moving that decimal over twice. A lot of people seem not to realize that a percent means parts out of 100.) That is giving us what is 10% of the 2100. If you already have the 210 and want to know what percent that is of the 2100, it means you have the "answer" to the above equation and it becomes 2100 * x = 210. The percent is missing. If we multiply to go forward, we start with the "answer" and divide to go backwards: 210/2100 = .10. (That will give the decimal version. You have to move it back over twice to put it back into a percent form of 10%.) So any time you want to know what percent x is of y, divide in that order: x/y. If you have the 210 and the 10% and you want to know what the original number was, then that's like this: x * .10 = 210. Again, to go backwards we divide: 210/.10 = 2100. So if you already have the portion of some other number and you want the original number, that is, x is y percent of what original number, again you divide in that order. Or you can learn it this way: Base = 2100, Rate = 10% and Part = 210. When doing a division, the part always come first in the division. 

Tags 
calculate 
Search tags for this page 
x as a percentage of y,x is what percent of y,how to find a x% of y,x% of y,x is what percent of y formula,what percentage of x is y,x as a % of y,how to find what percentage x is of y,finding x as a percentage of y,how to calculate x% of y,how to work out what percentage x is of y,x = what percent of y,what percentage is x of y,find x as a percentage of y,how to calculate what percentage of x is y
Click on a term to search for related topics.

Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
How to calculate!!!!  sajjad mt  Calculus  12  December 2nd, 2013 09:25 AM 
Calculate x  Chikis  Algebra  4  June 13th, 2013 09:03 PM 
To calculate the value of Z  pitrpan  Advanced Statistics  2  April 14th, 2011 01:09 PM 
calculate 1^2+2^2+...n^2  stole  Number Theory  3  August 15th, 2009 06:41 AM 
how calculate  Espanol  Algebra  3  April 2nd, 2009 10:03 PM 