sub second {
    my $num_ref = shift;

    my $sum = 0;

    my @newarray = ( 6 .. 10 );

    # try one of these options
    # foreach ( @$num_ref, 6 .. 10 ) {
    foreach ( @$num_ref, @newarray ) {
    $sum += $_;
    }

    return $sum;
}