title: Excel, how to increment row number for the SUM function?
body: <p>I have a Excel spreadsheet with original data in the range A1:A100</p>
  
  <p>I want cell B1 to be the sum of A1:A5, B2 = sum(A6:A10), B3 = sum(A11:A15)  and so on. What formula can I use for cell B1, that allow me to copy it to others B cells to achieve the above? </p>
  
  <p>Thanks and Regards,
  Nhan.</p>