my @numbers = (       '1',     '2',       '10',
                    '1.2',   '1e2',   '1.02e2',
                '1.02e-2',   'e-2',       'er',
                     'et',   '0er'              );

foreach my $number (@numbers) {
    my $test = $number;
    eval { $test +=0; };
    if ( $@ ) {
        print "$number isn't a number \n";
    }
}