Inserting Formulas Manually To insert formulas manually: Select a table cell by doing one of the following: Click inside a cell. Double click a cell. The cell switches to editing mode and the editing tools display. Starting with an equal sign (=), type the formula. The following examples list the functions you can use: =Sum (C3:D8). Adds the values from cells in rows 3 to 8, and columns C and D. =Average (C3:D8). Calculates the average of the values from cells in rows 3 to 8, and columns C and D. =Count (C3.D8). Counts the number of cells in rows 3 to 8, and columns C and D. =(C3+D3)/2. Adds the values of cell C3 and D3, and divides the result by 2. Press Enter to calculate the result. Parent topicInserting Formulas