9/80 = 11.25%
A value like 9/80 can show up as a discount, a survey result, or the share of a group that chose a particular option. For example, 11.25% of a class might prefer a certain lunch choice.
To picture it quickly, think of a little more than one-tenth of a whole. It’s close to 10%, but slightly larger—about one person out of every nine.
One common point of confusion is treating 11.25% as exactly 11% or exactly one-tenth. Those are useful rough estimates, but they’re a bit smaller than the actual value.