Name: Maureen Beard
Who is asking: Student

What is the origin of the terms numerator and denominater?

Hi Maureen,

There is a great Web site called Earliest Known Uses of Some of the Words of Mathematics that attributes the first use of these terms to Leonardo of Pisa in 1202. (I looked under N for numerator.) The quote is in Latin but the translation given is

When above any number a line is drawn, and above that is written any other number, the superior number stands for the part or parts of the inferior number; the inferior is called the denominator, the superior the numerator. Thus, if above the two a line is drawn, and above that unity is written, this unity stands for one part of two parts of an integer, i. e., for a half, thus 1/2.

I also looked in my dictionary. Numerator is a Latin word that means a number or a counter and denomerator means a standard or something held in common. So if you have a pizza and cut it into eight equal sized pieces then what each piece has in common is that it is one-eighth of a pizza. If the number of pieces you get to eat is three then you have three-eighths (3/8) of the pizza..

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