what is the numerator

The numerator is the top number in a fraction, representing the number of parts taken out of the whole. When numbers are written in the form of a fraction, it can be represented as a/b, where a is the numerator and b is the denominator. For example, in the fraction 4/5, 4 is the numerator and 5 is the denominator. The numerator is always written above the fraction bar or vinculum. It is the number of parts being considered out of the total number of parts in the whole.