title: Why is Perl's floor function off by 1?
body: <p>Perl's floor function is giving me unexpected results.</p>
  <p>floor(13320) = 13320, but floor(133.20 * 100) = 13319. I'd think both of those would get the same result. Why is this happening?</p>
  <pre><code>use POSIX;
  
  print floor(133.20);       # 133, as expected
  print floor(13320);        # 13320, as expected
  print floor(133.20 * 100); # 13319?
  </code></pre>