A percent is a ratio expressed as a fraction of 100. The root of the word is ‘cent’ which is Latin for 100. For example 55% is “fifty-five percent” is the same thing as 45/100, or the ratio 45:55.
If 50% of students are male, then that means in a class of 100, 50 are male. In a class of 10, 5 are male.
It is useful to think of things as a percentage. You can compare percentages of things together. Sales tax is percentage of the total sale. In Ontario, Harmonized Sales Tax (HST) is 13%. That means for every $100 of stuff that you buy, add $13 to the total which will go to the government.