0
$\begingroup$

This may seem really juvenile but I honestly am struggling.

I remember in school being taught this:

1% = X / 100

Then to figure out any percent times 1% by Y.

But if I substitute X to be 9.25 and Y to be 9.02 things get confusing.

9.25 / 100 = 0.0925 # this should be 1%
0.0925 * 9.02 = 0.83435

This led me to believe maybe if I * by 100 (to get 83.435%) I'd get the right answer. However I went onto this website: https://www.marshu.com/articles/calculate-percent-with-simple-number-percentage-calculator.php

and entering the values above it outputs 97.51% so now I'm a bit lost.

Sorry if this is really trivial, my maths level seems to be deteriorating the less I use certain areas :)

quick edit

I see that on their website the formula is

(X/Y) * 100

which in my case, using my numbers where X = 9.02 and Y = 9.25 it outputs 97.51% - however, was my maths eductation in school wrong for figuring out a percent with the (X / 100) * Y formula?

$\endgroup$
5
  • 1
    $\begingroup$ I have no idea what the formula $1\%=\frac X{100}$ is meant to mean. The usual situation is to have two values, $X,Y$. Say you have $7$ rotten apples in a basket of $32$. Then $X=7,Y=32$. If we wish to know what percent of our apples are rotten, we can compute the fraction, $\frac 7{32}$ or write it as a decimal, namely $0.21875$ or finally as a percent, namely $0.21875\times 100=21.875\%$. $\endgroup$
    – lulu
    Sep 12, 2018 at 11:03
  • $\begingroup$ @Lulu to find 1% of something you divide its value by 100... 1% of 32 apples is 0.32 apples. $\endgroup$
    – MRobinson
    Sep 12, 2018 at 11:04
  • 1
    $\begingroup$ @lulu $1\% = \frac X{100}$ means "one percent (of $X$) is $\frac{X}{100}$". It's a terrible way of writing it, but I think you've been on this site long enough and seen enough bad notation to understand the intent regardless. $\endgroup$
    – Arthur
    Sep 12, 2018 at 11:04
  • $\begingroup$ $1\%\neq\frac{X}{100}$ in general, but $1\%\times X=\frac{X}{100}$. Actually $\%=\frac{1}{100}$. $\endgroup$
    – drhab
    Sep 12, 2018 at 11:05
  • $\begingroup$ Ah, if that what is meant then I understand it. I thought the OP was trying to convert something to percent form. $\endgroup$
    – lulu
    Sep 12, 2018 at 11:11

1 Answer 1

4
$\begingroup$

Your two formulas are for two different things.

X/100 *Y will get you Y-percent of X.

To work out the percentage Y is of X then you do Y/X *100.

So when you have X = 9.25, Y = 9.02, then Y is 97.51% of X.

Where you have done 0.0925*9.02, that is you calculating 9.02% of X.

Let me know if that doesn't make sense.

$\endgroup$
0

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .