title: SSRS Formula or expression to change NaN to 0
body: <p>I am using the following expression to work out a percentage:</p>
  
  <pre><code>=Fields!Days.Value/Sum(Fields!Days.Value, "Date_month_name")
  </code></pre>
  
  <p>Days.Value is showing as 0 however in a few of my results instead of reading 0% in my percentage column it is actually reading NaN (Not a Number).</p>
  
  <p>Does anyone know the exact expression forumla i need and where I should paste it in my current expression to say "Where NaN is showing, put a '0' instead?"</p>
  
  <p>(See image)<img src="https://i.stack.imgur.com/U6Vce.jpg" alt="enter image description here"></p>