What do you mean by saying "Are you any good at maths"?

[مستر رمضان عيسى]

In this sentence, any is an adverb and means “to any degree or extent; at all”. So when you say “Are you any good at maths?”, it’s like saying “Are you good to any degree at maths?” or “Are you even a little good at maths?”

If you ask someone “Are you good at maths?” (without any), you’re asking if they are really good or very good. If you ask “Are you any good?”, you’re asking if they're a little good, if they’re not very good.

So if you need help with a maths problem, if the problem is not very difficult but you are horrible at maths, it might be sufficient for someone who is any good to help you. You might ask someone if they’re any good at maths (with any).

But if the problem is very difficult — whether you’re horrible at maths or not — and you need someone who is really good at maths to help you, you would ask someone if they’re good at maths (without any
taken from longman website