title: Regular expression for number and slash
body: <p>I do not know regular expressions and going crazy to find one that accepts formats consisting on numbers and slash. For example:</p>
  
  <ul>
  <li>5</li>
  <li>5/10 </li>
  <li>10/15/30 </li>
  <li>10/20/120 </li>
  <li>20/120/250/300</li>
  </ul>