We use the symbol % for "percent."

The word "percent" really just means "per hundred."

So, 25% means "25 per hundred" which is 25 / 100
 
.

If you had a pizza that was cut into 100 pieces, 25% of the pizza would be 25 pieces!

One pizza cut into 100 pieces...  Another pizza in fourths with each forth cut into 25 pieces...  Then, 1/4th of the pizza which is 25 pieces out of 100 which is 25% of the pizza!

A percent is just another way of counting part of a whole -- like fractions and decimals.

Check this out:

25% = 25 / 100 = ( 25 / 100 ) divided by ( 25 / 25 ) = 1 / 4

and

25% = 25 / 100 = .25

So, 25% is the same as

25 / 100   and   1 / 4   and   .25