[yesenadam]

I use "python calc" for quick calculations at the command line:

  pc () { python3 -c "print($*)" ; } 

  $ pc 3.5**2.4
  20.219169193375105

Or "awk calc", which seems much faster: (and ^ and ** both work for powers)

  calc () { awk "BEGIN{print $*}" ; }

  $ calc 3.5**2.4
  20.2192