Factorial

Score: 50.10 (pass)

#!perl -l
$z=$z*++$y%1e6,s~0*$~~for($z=1)x pop;print$z%10

Score: 50.10 (pass)

yes! 0.0008 improvement

#!perl -l
$~=$~*++$z%1e6,s|0*$||for($~=1)x pop;print$~%10

Score: 52.12 (pass)

#!perl -l
($z=$z*++$y%1e6)|s/0*$//for($z=1)x pop;print$z%10