use strict;
use warnings;
use Scalar::Util qw(looks_like_number isdual);
my $transf = '/3+6';
my $constant = '09';
my $var = \$constant;
#if (looks_like_number($$var)) {
if (!looks_like_number($$var)) {         #correction per [haukex]
    print "$$var is not a number\n";
}
else {
    print "$$var looks like a number\n";
}

if (!isdual($$var)) {
    print "$$var does not have a hidden numeric value\n";
} 


$$var =~ s/^0*//;   # make it into a valid number

my$expr = "$$var$transf";
my $ans = eval "$$var$transf";
print "$expr yields: ";
if (!$@) { 
    print $ans, "\n";
}
else {
    print $@, "\n";
}