title: Javascript float addition
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/588004/is-javascripts-math-broken">Is JavaScript&#39;s Math broken?</a>  </p>
  </blockquote>
  
  
  
  <pre><code>&lt;html&gt;
  &lt;body&gt;
  
  &lt;script type="text/javascript"&gt;
   var w = 0;
   var weight1 = parseFloat("0.6");
   var weight2 = parseFloat("0.3");
   w = weight1 + weight2;
  
   document.write("total weight: " + w);
  &lt;/script&gt;
  
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>Why does this print 0.8999999999999999  and not 0.90000000</p>