title: How to use expr on float?
body: <p>I know it's really stupid question, but I don't know how to do this in bash:</p>
  
  <pre><code>20 / 30 * 100
  </code></pre>
  
  <p>It should be <code>66.67</code> but expr is saying <code>0</code>, because it doesn't support float.
  What command in Linux can replace expr and do this equalation?</p>