Fractions are ratios; they need an additional number to tell you what number the fraction represents. The number can be an integer or not; the fraction itself is not an integer.
E.g. 1/2 of the students in a class are expected to be above the national average. That does not tell you how many students should be above-average for your class to meet national standards.
If I additionally tell you that there are 27 students in the class, that does tell you how many students, but the number is not an integer. You end up expecting 13.5 students to be above average, which is nonsensical until you round up or down to come to a number that can mean anything.