on *:TEXT:!calc *:#:{ 
  set %calc [ $+ [ $nick ] ] $calc($2-)
  notice $nick $2- $+ $chr(32) $+ = $+ $chr(32) %calc [ $+ [ $nick ] ]
unset %calc [ $+ [ $nick ] ] }

on *:TEXT:@calc *:#:{ set %calc [ $+ [ $nick ] ] $calc($2-)
  msg $chan $2- $+ $chr(32) $+ = $+ $chr(32) %calc [ $+ [ $nick ] ]
unset %calc [ $+ [ $nick ] ] }