verb after "a number of"

Can one use a singular verb after "a number of", or is it always a plural?
(I.e. is there a situation when "A number of xxx is..." when one is looking at
"a number of xxx" as one group?)

[MrPedantic]

Hello 123

In British English, I would expect a plural verb, e.g.

1. A number of other members are reading this post and shaking their heads in disbelief at MrP's answer.

2. A number of bottles still remain in my fridge. I may open another one in a minute.

3. A number of dancing girls have just knocked on my front door.

At least, I can't think of an example with a singular verb. But perhaps another member can!

MrP