2403/2403 = 100%
A fraction like 2403/2403 shows up when every item in a group is accounted for or completed. For example, if all 2,403 students submit a required form, the completion rate is 100%.
You can picture it as a completely filled progress bar, with no missing space at all. A quick estimate is easy because the top and bottom numbers are identical, so the fraction represents one whole.
One common confusion is thinking the large numbers make the percentage greater than 100%. They do not; when the numerator and denominator match, the value is exactly one whole, or 100%.