This should help:

Quantum analogue computing - PDF

We could say that discrete mathematics pairs better with digital systems (for obvius reasons) than with analogue ones.

And continuous mathematics pairs better with analogue systems.

So in classical physics there is much use of continuous mathematics than in quantum physics and vice-versa.

A digital computer doesn't need to simulate discrete maths, but it does need to simulate continuous maths. An analogue computer would have trouble to simulate a discrete maths problem, but it's better suited for continous maths.

When some people wonder how was it posible to get complex space travel missions done in the 1960's, they are thinking on digital computers performing certain computational tasks, when in reality were done by analogue computers. They try to figure out certain functions performed by digital computers, but thoses specific functions performed by analogue computers requerid by far less resources.