title: PHP round crazy bug
body: <pre><code>&lt;?php
      $last_percent = 0;
      $as = array("110.800002098083",  "30", "36.1499996185303", "11", "13", "13.9899997711182", "74.5200042724609", "13.9899997711182");
      $t = 304.46000552177;
      foreach($as as $a) {
          $last_percent += round($a*100/$t, 2);
      }
      var_dump( $last_percent);
      $last_percent = 100 - $last_percent;
      var_dump( $last_percent);
  ?&gt;
  </code></pre>
  
  <p>why results is 0.33000000000001? why it only happen with 100 and 99? if i use $last_percent = 90 - $last_percent;
  results is -9.67</p>