Every value of the type float, except NaN and perhaps +inf and -inf
(depending on which version of the Real Number Line you use) IS actually
a representation of a Real Number (so I don't understand in what way you
can say they aren't "numbers"). And yes, they happen to also be Rationals.
This is not subtle, and it is not something you do not understand. C'mon.
Tell me three Real Numbers (or Rational Numbers) such that:
(a + b) + c != a + (b + c)
You will not succeed in that endeavor because of the nature of "numbers."
... and yes, because of the usual meaning given to the symbol '+', etc.
OK... now I'll tell you three floating point "numbers" that follow that pattern:
a = float("0.1")
b = float("0.2")
c = float("0.3")
We can conveniently write the constructors for these in Python as `0.1` and so on. These objects that occupy computer memory are not "numbers" in the sense of obeying the axioms of arithmetic. But they kinda-sorta resemble numbers, and computers can do things with them quickly, so we pretend.