&spl($total) if ($len != 1);

##</code><code>##

$total = &spl($total) if ($len != 1);

##</code><code>##

sub spl {
   my ($num1) = @_;    
   while (1) {
      my $total = 0;
      $total = $total + $_ for (split '', $num1);
      my $len = length ($total);
      if ($len == 1) {
         return $total;
      }
      $num1 = $total;
   }
}

##</code><code>##

sub spl {
   my ($n) = @_;    
   while (length($n) > 1) {
      my $total = 0;
      $total = $total + $_ for split '', $n;
      $n = $total;
   }
   return $n;
}

##</code><code>##

use List::Util qw( sum );

sub spl {
   my ($n) = @_;    
   while (length($n) > 1) {
      $n = sum split '', $n;
   }
   return $n;
}