I am stuck on this one Emotion: sad
I believe that in using number I have to put the following noun at its plural form, so in my case:
number of unique openings

But it sounds strange to me Emotion: sad
Should I use:
number of unique opening

Which form is correct in my case?

thxs in advance
"Opening" is a countable noun, so "openings" is correct if the number of openings is two or more.
Expressions such as:
- a number of
- a large/small number of
- the number of
- large/small numbers of
are followed by a noun in the plural ("a number of" can refer only to countable nouns).

"Large numbers of/A large number of teachers attended the seminar."
"This killing brings the number of deaths this year to 26."
"A number of (=several) well-qualified people have recently left the company."
"The number of unique openings increased last month."
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well done, teacher
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