For this case, we have to, by definition:
The numerator: Is the number that, in a fraction, indicates the equal parts of the unit that contains that fraction. It is located at the top of the fraction.
The denominator: It is the number that, in a fraction, indicates the equal parts in which the unit is considered divided. It is at the bottom.
Example:
Let the fraction
The numerator is "a" and the denominator is "b".
Answer:
Numerator: Top
Denominator: Bottom