Is there any explanation of how the human brain calculates arithmetical problems? It is true that the brain greatly outperforms the calculator, but it is apparent that humans make mistakes even with simple math problems, and take longer to answer, whilst the calculator just runs a bunch of bits through logic gates and pops out a correct result almost instantaneously.

Considering the above statement, it seems apparent that the human mind takes a completely different approach to arithmetic problems than the calculator.

Has there been any research that at least provides a general idea of the brain's approach?
What I know is that there is evidence that the brain treats arithmetics very similarly as language. I also know that there is a cortical area more akin to encoding the sense of numerosity, which could be accessed while performing arithmetic calculations. However, I am no expert in the area and only know of some works done by some colleagues that I'll link here.


Eye gaze reveals a fast, parallel extraction of the syntax of arithmetic formulas
When order matters: Last-come first-served effect in sequential arithmetic operations
The cortical representation of simple mathematical expressions


If you are interested, you should look at Stanislas Dehaene's work. He has many papers on how the brain does math and how it also is able to naturally encode numbers.