A * B = 20
A * C = 40
A * D = 8
A * E = 36
B * A = 20
B * C = 50
:
:

##</code><code>##

    for my $x (sort keys %hash) {
        for my $y (sort grep { $_ ne $x } keys %hash) {
            printf "%s * %s = %d\n", $x, $y, $hash{$x} * $hash{$y};
        }
    }