As the articles that you've already been pointed to say, computers use a float-binary representation. The number 1/10 does not have an exact representation in base-2 floats, much as 1/3 does not have an exact representation in a base-10 float. Computers can handle this problem by using decimal (BCD = Binary-Coded Decimal) arithmetic, but Perl does not directly expose this type. One pragmatic solution to your problem might be to count using integers, where the integer is the desired number multiplied by 100. Then, each time, calculate the float by casting the integer to a float and dividing it by 100. Because this is done each time, errors do not accumulate. Many database systems employ a variation of this "scaled integer" strategy to handle their currency data type.

In reply to Re: While loop with addition goes weird by Anonymous Monk
in thread While loop with addition goes weird by chiel

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.