my $str = '1029576843';
my @f = split //, $str;
for (@f)
{
  #$_ is now 0; next run will be 1 and so on
  print;
}
#or
for my $current_number (@f)
{
  #$current_number is now 0; next run will be 1 and so on
  print $current_number;
}