This is an issue with Perl, not with this module. Huge numbers get converted to floats automatically by Perl. You can't convert back, as you suggest, because you've lost accuracy: 
$ perl -e 'print 10000000000000001, $/'
1e+16
$ perl -e 'print 10000000000000005, $/'
1e+16
$ perl -e 'print 10000000000000000, $/'
1e+16

[download]
You will find that every module on CPAN that needs to deal with integers this big either (A) requires you to pass the number as a string, or (B) uses Math::BigInt or similar, to prevent Perl from converting the integer to a float. Even notice from Math::BigInt's pod: 
Scalars holding numbers may also be passed, but note that non-integer 
+numbers
may already have lost precision due to the conversation to float. Quot
+e your
input if you want BigInt to see all the digits:

        $x = Math::BigInt->new(12345678890123456789);   # bad
        $x = Math::BigInt->new('12345678901234567890'); # good

[download]

blokhead

In reply to Re: Number::Spell by blokhead
in thread Number::Spell by PERLscienceman

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.