Use of Autosum feature
Autosum feature (invoked by clicking on the upper-case Greek sigma)
works slightly differently in one respect in Calc than in Excel.
either Excel or Calc, you can select an empty cell, generally just
below the bottom of a range containing numbers to be summed (or to
the right of a range of numbers to be summed). When the Autosum
button is clicked, Excel or Calc will propose a range to be summed,
which in many cases, is in fact the range the user intended. If this
is the correct range, pressing Enter will enter the SUM
function into the cell. If the proposed range is not what the user
intended, the user can highlight the range desired, then press Enter.
There is no difference between Excel and Calc when using the Autosum
as described above.
Excel, you can also first highlight the range to be summed plus one
additional blank cell, then click Autosum. The SUM function will then
be entered in the previously blank cell. This use of Autosum is not
available in Calc.