# Zero Percent of 100

In the equation:

$$5 \times 100 / 1$$

You see that $5$ over $1$ is a $500\%$ increase. How would I show the percent of increase over zero? Thank you.

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Sorry if this is a stupid question. I am just asking if it is possible to show a percent of increase over zero. I see that I cannot divide by zero, so is it not possible? –  user1477388 Oct 30 '12 at 14:42
If originally you had zero piece of something, then you get 2 of these something, then the increase is $\infty\%$. Is it what you're asking? –  Berci Oct 30 '12 at 14:44
Yes, that is what I'm asking. It's hard for me to understand "infinite %." Aren't zero and one only one digit from each other? How can 0 be infinite % from 5 when 1 is 500% from 5? –  user1477388 Oct 30 '12 at 14:48
Question: 5 is what percent increase over 0 ? This is a division problem with divisor 0. Not allowed. Any percent increase of zero is still zero. Sometimes a guy I know (who is a volunteer worker, unpaid) says "I want a raise" and the boss says "I'll double your salary" and we all laugh. –  GEdgar Oct 30 '12 at 14:56
Thanks to everyone for helping me understand :) –  user1477388 Oct 30 '12 at 14:59

$500$% increase means that provided that you previously had $x$ amount of something, then it became $5$ times itself.
$500$% increase 'over $0$' thus means that you had $x=0$, and finally it became $5x$ which is still $0$.
Increase from $0$, hence is not measured well by the ratio of increasement, but the increasement itself. And, percentage can describe only ratios.