Secret Number

Score: 69.00 (pass)

#!/usr/bin/perl -l
$_=pop;print,s/./($z=$&+chr ord$')>9?$z-9:$z/eg,chop while length;

Score: 111.00 (pass)

#!/usr/bin/perl
$_=pop;l:print"$_
";(@_=split//)>1||exit;$_='';
($z=shift(@_)+$_[0])>9&&($z%=9 or$z=9),$_.=$z while@_>1;goto l;