use Data::Dumper;
use strict;

my $hash = {};
for (1..100) {#keys are all numbers, from the users' point of view
        $hash->{$_} = "a";
}

my @keys = keys %$hash;#this is the internal order, I don't care
print(join(",", @keys));
print "\n", "=" x 70, "\n";

my @sorted = sort @keys;#this will sort as strings!!
print(join(",", @sorted));
print "\n", "=" x 70, "\n";

my @sorted_as_num = sort {$a <=> $b} @keys;#force it to sort as number
print(join(",", @sorted_as_num));
print "\n", "=" x 70, "\n";

print Dumper($hash);