what is a numerator

A numerator is the top number in a fraction, which represents the number of parts 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 smaller than or equal to the denominator. Numerators are used to represent parts of a whole, and they can be used to perform mathematical operations such as addition, subtraction, multiplication, and division with fractions.