In [1]: import numpy

In [2]: a = numpy.array([[1, 0], [10 ** 20, 1]])

In [3]: b = numpy.array([[10 ** (-20), 1], [0, 1 - 10 ** 20]])

In [4]: a
Out[4]:
array([[1, 0],
       [100000000000000000000, 1]], dtype=object)

In [5]: b
Out[5]:
array([[1e-20, 1],
       [0, -99999999999999999999]], dtype=object)

In [6]: a @ b
Out[6]:
array([[1e-20, 1],
       [1.0, 1]], dtype=object)