# Percentages -- having trouble understanding how to take a percentage of a number

1. Apr 17, 2016

### zak100

1. The problem statement, all variables and given/known data

What is 'a' divided by a% of a?
2. Relevant equations

a div a/a * 100
3. The attempt at a solution
a/1/a/a * 100 = a/100

which is not a correct answer. I cant define a%. In my view a% of a means 100 i.e. a/a * 100.

Zulfi.

2. Apr 17, 2016

### SteamKing

Staff Emeritus
How would you express a% as a decimal number? Hint: what is 50% of something as a decimal number?

3. Apr 17, 2016

### Ray Vickson

For a general value $x$, what would be $a\%$ of $x$? What would you get if you then put $x = a$?

4. Apr 17, 2016

### zak100

Hi,

a% of x = a/x * 100
if x = a , i would get 100.
<
How would you express a% as a decimal number? Hint: what is 50% of something as a decimal number?
>
I know about 50% as 0.5. I got this knowledge from the forum last time. But i dont know how to express a%, maybe 0.0a????

Zulfi.

5. Apr 17, 2016

### Ray Vickson

No, you have it wrong. 50% of 50 is one-half of 50, which is 25. 10% of 10 is one-tenth of ten, which is 1.

6. Apr 17, 2016

### zak100

Hi,
<50% of 50 is one-half of 50>
= 0.5 (50)
what about a% of a = (a/100 )* a.
Is the above correct?
Yes, $a\%$ of $a$ is $(a/100)a = a^2/100$, just as you wrote.