title: Batch File Techinque for Set /A and quoting
body: <p>I've always wondered about how and when to use quotes if my script is making a calculation. For example,</p>
  
  <p><code>Set /A exp=%some%+(!calculation!-0)</code>.</p>
  
  <p>I know, if the line uses parentheses, and I'm inside an <code>IF</code> block, I should use</p>
  
  <p><code>Set /A exp="%some%+(!calculation!-0)"</code>.</p>
  
  <p>The quotes just go around the part after the equals.</p>
  
  <p>Aside from that, quoting from the variable name to the end of the line,</p>
  
  <p><code>Set /A "exp=%some%+(!calculation!-0)"</code></p>
  
  <p>seems to work as well.</p>
  
  <p>I'm wondering, is there a "proper" way to use <code>SET /A</code>? What's the <em>correct/best</em> technique for batch scripts? When should I use quotes? Are they mostly optional unless one gets an error?</p>
  
  <p>Thank you.</p>