title: Shell: how to evaluate an arithmetic expression with more than two operands
body: <p>I have read several posts but they are talking about two operands</p>
  
  <p>I have got the following expression that is to be evaluated:</p>
  
  <blockquote>
    <p>sum = a / b * 100</p>
  </blockquote>
  
  <p>In the bash shell, I can do:</p>
  
  <pre><code>bash-4.1$ a=5
  bash-4.1$ b=10
  bash-4.1$ sum=`expr $a / $b`
  bash-4.1$ echo $sum
  0
  </code></pre>
  
  <p>However, I cannot do:</p>
  
  <pre><code>bash-4.1$ sum=`expr $a / $b * 100`
  expr: syntax error
  </code></pre>