my %hash;

@hash{a..f} = 10..15;

sub a {
    my $a_count;
    while( my ($k,$v) = each %hash) {
        print "$k => $v\n";
        $a_count++;
    }
    $a_count++;
}
sub b {
    my $b_count;
    while( my ($k,$v) = each %hash) {
        $b_count++;
        print "$k => $v ($b_count out of ", a(), ")\n";
    }
}
b()
__END__
c => 12
a => 10
b => 11
d => 13
f => 15
e => 14 (1 out of 5)
c => 12
a => 10
b => 11
d => 13
f => 15
e => 14 (2 out of 5)
c => 12
a => 10
b => 11
d => 13
f => 15
e => 14 (3 out of 5)
...