57/58 as a percentage is 98.28%. This fraction is just a tiny bit less than a whole, so when you look at it in terms of percent it’s almost perfect—just under 100%.
The fraction 57/58 shows how close 57 comes to 58, and that closeness is reflected in the percentage. When you see 98.28%, you can picture it as 98.28 out of every 100 parts, which is a very high proportion.
In everyday language, you might hear people say “about 98%” when they want to describe something that’s nearly complete. Using 57/58 gives you a precise way to talk about that same idea with exact numbers.