How do you do Sigma operations in an Open Office Spreadsheet?

In an Open Office Spreadsheet, you can perform Sigma (summation) operations by using the SUM function. To do this, select the cell where you want the result to appear, type =SUM( followed by the range of cells you want to add (e.g., A1:A10), and then close the parentheses. Press Enter, and the sum of the specified range will be calculated and displayed in the selected cell. Alternatively, you can use the AutoSum feature by selecting the cell below or next to the range and clicking on the Sigma (Σ) icon in the toolbar.