What is the term for the number below the line in a fraction?

The term for the number below the line in a fraction is known as the denominator. In any fraction, the structure consists of two main parts: the numerator, which is located above the line and represents how many parts of a whole you have, and the denominator, which indicates the total number of equal parts the whole is divided into. The denominator is crucial as it dictates the size of each part and, therefore, the value of the fraction itself.

For example, in the fraction 3/4, the number 4 is the denominator, telling you that the whole is divided into 4 equal parts, while the numerator, which is 3, tells you that you have 3 out of those 4 parts. This fundamental understanding of fractions is essential in various mathematical applications, making the concept of the denominator particularly important in both theoretical and practical contexts.