Documentation of the numbers module:
https://docs.python.org/3/library/numbers.html
states "None of the types defined in this module can be instantiated."

This is true for Complex, Real, Rational, Integral but not for Number:

>>> numbers.Number()
<numbers.Number object at 0x7fcccc71f3c0>
>>> numbers.Real()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: Can't instantiate abstract class Real...

Since Number doesn't have any abstract methods, the correct fix seems to be changing the documentation. I would try to convey something like this:

"The types defined in this module can be used for subclassing and checking whether a specific class is in the numeric hierarchy; they are not used directly for instantiation. For this, you can use types such as `complex` or `fractions.Fraction`".