title: How to add two strings that are numbers?
body: <p>i am looping through some nodes and getting the charge and adding them together. the charge is of type string though.</p>
  
  <p>first time it loops string charge = "309",</p>
  
  <p>second time it loop string charge = "38";</p>
  
  <pre><code> `Looping through list of nodes
   {
     saBillDetail.TotalServiceUsage += totalSvcNode.InnerText;
   }
  `
  </code></pre>
  
  <p>I would have expected that I could add them together, but they are being concatenated instead like this:</p>
  
  <pre><code>`charge + charge = '30938'`
  </code></pre>
  
  <p>How can I force these strings to be treated as numbers? and get output like this at the end of the loop</p>
  
  <pre><code>`charge + charge = '347'`
  </code></pre>