title: php round a number
body: <p>I have a variable </p>
  
  <pre><code>$amount = 621.00;
  </code></pre>
  
  <p>I need the 30% of the variable with output 186.30</p>
  
  <p>When I calculate:</p>
  
  <pre><code>$amount2 = round($amount*30/100 , 2);
  
  echo $amount2
  </code></pre>
  
  <p>gives the output of 186.3</p>
  
  <p>how can I have output 186.30</p>