9/80 as a percentage is 11.25%. This value tells you how much of a whole the fraction represents when you think in terms of hundredths.
The fraction 9/80 is a simple way to show a part of something that is divided into 80 equal pieces. If you had 80 pieces of a pizza, 9 of those pieces would be the same amount as 11.25 out of every 100 pieces.
In everyday life, percentages like this are useful for quick comparisons. For example, a test score of 9 correct answers out of 80 questions would be reported as an 11.25% score.
Remember that percentages are just another way to talk about fractions, making it easier to see how big or small a part is relative to a whole.