# Numerator vs. denominator vs. nominator

What is appropriate usage of "numerator", "denominator", and "nominator" to refer to parts of a fraction?

I'm posting this question and answer here because I had little luck finding a clear answer through Google. I realize that it's not really mathematics, but I think it's worth mentioning as an educational issue.

Ideally, the question at English.stackexchange would address this completely, however they have closed it with the reason: "you can just look it up". I agree that this is possible, but I don't think that reveals the consensus. I wanted to allow for more opinions to be expressed. (Below, I argue that "nominator" should be discouraged.)

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I this is triggered by a recent comment of mine I apologize for causing this. It is in fact easy to look up these terms (e.g. at www.dictionary.com, which supports your position. I have no problem whatsoever with using numerator and do admit that using nominator was the result of a moment of thoghtlessnes of a non native speaker. –  user20266 Jun 16 '12 at 14:44
Hi @Thomas No no, this post was not wholly caused by you :) You are actually the third incident that I have run across this recently, and so I started searching previous posts and I figured we could use a post to refer to on the topic. Please don't feel picked on: rather feel that you inspired me to action! I did not intend to make you feel like a troublemaker :) –  rschwieb Jun 16 '12 at 14:46
I see, now I'm 'an incident'! ;-) Thanks for the clarification –  user20266 Jun 16 '12 at 14:48
Henceforth, this shall be known as "the @Thomas incident"! –  The Chaz 2.0 Jun 16 '12 at 14:54
@TheChaz I saw this coming, kind of, thank you! rschwieb: are you implying, then, that the remaining 1% of these 'incidents' are to be considered mischievous, and this even by intention? What a gruesome observation! –  user20266 Jun 16 '12 at 15:07

It would be amusing, for fractions such as $1/(a/b)$, to call $a$ the nominator and $b$ the denumerator. Admittedly, this twisted symmetry with normal usage is perverse, but I am currently grading exams and so feel entitled to a bit of perversity. –  Harald Hanche-Olsen Jun 16 '12 at 14:37