title: how to round to nearest 50 or 100?
body: <p>I have numbers (in decimal) I want to round it to "nearest 50":</p>
  
  <ol>
  <li>122 => round to 150</li>
  <li>177 => round to 200 </li>
  <li>157 => round to 200 </li>
  <li>57 => round to 100;</li>
  <li>37 => round to 50; </li>
  <li>1557 => round to 1600</li>
  <li>3537 => round to 3550</li>
  </ol>
  
  <p>how to do that with java/groovy ?</p>