Can someone please explain irrational/rational/ natural/ whole numbers?

Yeah thats fair enough. It's tricky to put it at the right level. Also similarly to the other replies about a circular definition.

I would say something like that an irrational is a number with an infinite number of seemingly random decimal places. I guess theres an implication that 'number' refers to a real, but there's probably no need to divulge that at this level.

For an informal definition of a real I was going to say 'any number you can think of', but then you'd have to consider whether the audience thinks of sqrt(-1) - im sure theres a joke in there somewhere, "a magician walks into a bar and asks someone to think of a number..." and the mathematician ends up with a black eye because they thought of i*pi + sqrt(2)!

I guess you could say that a real number is any number your everyday pocket calculator can deal with? Without going into a rabbit hole of finite precision and approximations.

For OP, an interesting fact is that between 0 and 1, there are both an infinite number of rational numbers and an infinite number of irrational numbers.

/r/learnmath Thread Parent