We get many questions along the lines of "how do I frame a question in order to elicit an ordinal number as a response?". And, inevitably, they are all closed as duplicates of:
I want to make a question having an answer as follows:
5 is the third prime number.
The bold part is the answer. How to phrase the question?
Whose top-voted, but not accepted, answer is (summarized):
The number two is the first prime number. In the sequence of prime numbers, what is the position of the number five?
That is, this question, and this answer, are the de facto "canonical versions" of this common inquiry on EL&U.
I don't think the current "canonical" question is the best representative, and I don't think the "canonical" answer(s) are the standard, natural way native speakers would frame the question.
To illustrate my point, the answers of the ‘canonical’ question are in bold while the linked "answers" are each taken from one of the duplicate posts.
(I hope you agree that none of questions in bold could possibly lead a person to reply: I am the third eldest daughter, or, I came fifth in the race.)
Question: What ordinal number reflects the position of the number five in the set of prime numbers?
Question: The number two is the first prime number. In the sequence of prime numbers, what is the position of the number five?
Question: For the sentence “5 is the nth prime number” to be correct, what should be the value of n?
Question: What is the position of 5 in the sequence of prime numbers?
If you agree that the questions and answers are appropriate and correct; please leave the following questions closed as a duplicate of the canonical question above. However, I would suggest that we identify a new "canonical" version of this question.
List of closed questions as being duplicates of current de facto "canonical" question.
My preference is to elect question number 1 (Framing a question whose answer is an ordinal number) as the new canonical question, and linking all the other questions to that one. It has four practical sensible answers, and nine upvotes. It might also be an idea to merge this post with question number 2 (How to ask about ordinal place of an offspring?).
The answers in the two questions do not clash, and they are not carbon copies of each other. Moreover, users will see this wise observation: “There isn't really a simple way of asking this in English, ...”. It also helps to explain why the terms; manieth, manyth, or nynth do not exist in the English language.