When you turn 69/70 into a percent you get 98.57%. That’s the answer to “What is 69/70 as a percentage?” and it shows how close the fraction is to a full 100%.
A value of 98.57% means the fraction is almost the whole. It’s just a tiny bit less than one, which is why the percentage is so high.
In everyday terms, think of a test where you answered 69 out of 70 questions correctly. Your score would be 98.57%, which would almost certainly be an A.
Because the number is rounded to two decimal places, the exact value might be a little different, but for most uses 98.57% is precise enough.