title: Unexpected behavior of expr
body: <p>It may sound a bit trivial but it actually is quite frustrating:
  Can anyone explain me this:</p>
  
  <pre><code>
  [~:user$]expr 3 + 2
  6
  [~:user$]expr 3 / 2
  1
  [~:user$]expr 3 * 2
  expr: syntax error
  </code></pre>
  
  <p>When the man page for <code>expr</code> precisely specifies that ARG1 * ARG2 is arithmetic product of both.  </p>
  
  <p>Thanks,</p>