Hello seki,

I read that you found your answer already to your question, but I think it is interesting to read also perlnumber, integer or even casting the numbers with int.

Related to your question, just a simple example:

#!usr/bin/perl
use say;
use strict;
use warnings;
use Math::Roman qw(roman);
use Scalar::Util qw(looks_like_number);

my @array = ("8", "", 8, "132.8", 132.8, "III", roman('III'));
foreach my $array_element (@array) {
    if (looks_like_number($array_element)) {
    say "Element: ".$array_element." is a number";
    } else {
    say "Element ".$array_element." isn't a number";
    }
}

__END__

$ perl test.pl
Element: 8 is a number
Element  isn't a number
Element: 8 is a number
Element: 132.8 is a number
Element: 132.8 is a number
Element III isn't a number
Element: III is a number
[download]

I used Math::Roman and Scalar::Util. Also this is a frequently asked question perlfaq4/How do I determine whether a scalar is a number/whole/integer/float?.

Similarly asked question A function to determine if a string is numeric.

Hope this helps, BR.