13/16 = 81.25%
The fraction 13/16 represents 81.25%, a value that can show up when most of something is complete. For example, if 13 out of 16 students turn in an assignment, or 13 of 16 seats are filled, the amount is a little more than four-fifths.
To picture 13/16 quickly, imagine a whole divided into 16 equal parts with 13 shaded. It is close to 80%, but slightly higher, so you can estimate it as about four-fifths of the whole.
A common mistake is to round 13/16 to 80% and treat that estimate as exact. The difference is only 1.25 percentage points, but it can matter when the value is used for grades, measurements, or detailed comparisons.