grammatical number - How to explain why do we use, e.g. "1" video but "0" videos?

It's getting really complicated when you have to explicate to a student a bunch of habitual "Whys"!

For example, how do I explain, why do we say: "1 video but 0 videos?".

It's understood, if we say 2 videos but when we refer to '0' why is it also plural?