title: Why 2.4 mod 0.8 returns 0.8
body: <p>Why modulus calculation of 2.4 by 0.8 returns 0.8? Shouldn't it return 0?</p>
  
  <p>It happens both in PHP, via <code>fmod</code>, and JavaScript, via <code>%</code>.</p>
  
  <p>Even a google research with this operation fails: <a href="http://www.google.com/search?q=2.4+mod+0.8" rel="noreferrer">http://www.google.com/search?q=2.4+mod+0.8</a></p>