open my $in, '<', 'numbers.txt' or die $!;

  #  local $/;    # slurp mode
    my @data = <$in>;
    chomp @data;
    close $in;

sort_num(@data);
my @new_sort=sort_num();
print "this is new sorted data ;",@new_sort;

sub sort_num{
    my @sorted=sort {$a <=> $b}@_;
   return @sorted;
    }

##</code><code>##

Argument "2 3 3 3 5 7 8 12 32 44 55 12 3 23 43 33 1 4 25 43 42 1" isn't numeric in sort at C:\Users\Alberto\Documents\NetBeansProjects\PerlProject\Perl Essentials\subroutines\ave_mode_median_range sub.pl line 24.
this is new sorted data ;