Question

which type of package is calc​

Answer 1

Answer:

calc – Simple arithmetic in LATEX commands

Adds infix expressions to perform arithmetic on the arguments of the LATEX commands \setcounter, \addtocounter, \setlength, and \addtolength. Since many packages start their arithmetic by storing an argument in a register, the package has wide applicability.

This package is part of the latex-tools bundle in the LATEX required distribution.