title: Sum of row n through last row
body: <p>I want to create a TOTAL row at the top of my spreadsheet.  In this row, each cell should be the SUM of the values in the column below the TOTAL row.  </p>
  
  <p>So for example, if the total row is Row 1, cell A1 should be the SUM of A2 through the last row in column A. The number of rows in the spreadsheet will grow over time, so I can't just say <code>SUM(A2:A500)</code> because eventually there will be row 501, 502, etc.</p>