The calculator on Linux CLI
Comma vs point
On the num-pad I've a comma assigned to the separator key. BC only accepts decimal points. This alias remaps the command with a dot for when bc starts and back when it ends.
alias bc='xmodmap -e "keycode 91 mod2 = KP_Delete period"; bc -l; xmodmap -e "keycode 91 mod2 = KP_Delete comma"'