title: round number to 2 decimal places
body: <p>I need to round a number to two decimal places.
  Right now the following rounds to the nearest integer I guess</p>
  
  <pre><code>puts [expr {round($total_rate)}]
  </code></pre>
  
  <p>If I do something like below it does not work. Is there another way around?</p>
  
  <pre><code>puts [expr {round($total_rate,2)}]
  </code></pre>