27/30 = 90%
A value like 27/30, or 90%, might describe a score on a quiz, how much of a phone battery remains, or how many items in a batch passed inspection. It shows that nearly all of the whole is accounted for, with a small portion left over.
To picture 90%, imagine a strip divided into ten equal boxes: nine would be filled. You can also think of it as just a little less than the whole, which makes it easy to estimate at a glance.
One common mix-up is treating 90% as if it means 90 out of 30, rather than 90 out of 100. The fraction 27/30 is also exactly 9/10, so it represents the same share even though the numbers look different.
