You may want to have a look at my module Number::Format::Calc.

use Number::Format::Calc ( -thousands_sep=>"", -decimal_point=>",");
use strict;
use warnings;

while (<DATA>)
{
    my $n = new Number::Format::Calc ($_);
    print $n * 2, "\n";

}
__DATA__
1,1
2,2
3,3
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Output:

2,2
4,4
6,6
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