title: how to add a value to a parameter without quotes
body: <p>I'm using SASS to generate some styles, but I can't figure this one out. </p>
  
  <p>Example:<code>$v: round(($s / 12) * 100) + "%";</code></p>
  
  <p>results in: <code>width: "25%";</code></p>
  
  <p>but I want it to result in <code>width: 25%;</code></p>