title: Rounding error in Python with non-odd number?
body: <p>I'm beginner in Python, and I have one question.<br>
  Why does rounding a number like 5.5, 7.5, (anything).5 with odd integer part applying <code>round(num)</code> work correctly (rule 5/4), but rounding number like (anything).5 with non-odd integer part by the same function returns just an integer part?
  (But if we add a little number like 0.000000001 to that decimal number it works correctly)</p>
  
  <p>I mean the next:</p>
  
  <pre><code>round(9.5)
  </code></pre>
  
  <p>returns 10, and it's correct. But</p>
  
  <pre><code>round(8.5)
  </code></pre>
  
  <p>returns 8, and it isn't correct. And</p>
  
  <pre><code>round(8.5 + 0.0000000000001)
  </code></pre>
  
  <p>returns 9.</p>
  
  <p>Why it works incorrect?<br>
  I use Python 3.2.2 at Windows.</p>