Question

Which part of system unit does all the mathematical calculation

Answer 1

Heya!!
That is done by CPU




Hope it helps you.

Answer 2

" ALU ("Arithmetic and Logic Unit") is the "part" of system unit that does all the mathematical calculation.  "Arithmetic and Logic Unit" (ALU) forms as the fundamental unit in "Central Processing Unit" (CPU). It is responsible to "perform" bitwise and arithmetic operations on any given integer.

    The arithmetic calculations includes all the basic addition, subtraction, multiplication, and logical operations such as OR and AND."