bc(1) - An arbitrary precision calculator language
-i, --interactive
       Force interactive mode.
-l, --mathlib
       Define the standard math library.
-w, --warn
       Give warnings for extensions to POSIX bc.
-s, --standard
       Process exactly the POSIX bc language.
-q, --quiet
       Do not print the normal GNU bc welcome.
-v, --version
       Print the version number and copyright and quit.
var = expr
       The variable is assigned the value of the expression.