title: Excel SUM function for currency
body: <p>The cells I want to sum are:</p>
  
  <pre><code>A1 =DOLLAR(10.45)
  B1 =DOLLAR(10)
  </code></pre>
  
  <p>When I use the SUM function:</p>
  
  <pre><code>=SUM(A1+B1)
  </code></pre>
  
  <p>It works, giving me 20.45. But If I do:</p>
  
  <pre><code>=SUM(A1:B1)
  </code></pre>
  
  <p>I get a #VALUE! error.</p>
  
  <p>I have two questions:</p>
  
  <ol>
  <li><p>Why is the behavior different between the two formulas? Why does making it a range change the way the cell values are interpreted?</p></li>
  <li><p>Is it possible to write a function that uses a range to SUM dollar amounts?</p></li>
  </ol>