use warnings;
my $cmd = "cmd";
my $value = qx($cmd);

my $cmd1 = "cmd1";
my $value1 = qx($cmd1);

if (($value+0) eq $value) {
print $value . " is numeric";
}
else
{
print $value . " is not numeric";
}

if (($value1+0) eq $value1) {
print $value1 . " is numeric";
}
else
{
print $value1 . " is not numeric";
}

my $total = $value + $value1;
print $total;   // this gives me total of two values.