The Sum tool allows the user to calculate the sum of the cells. It can be used in two ways.
First the cell in which the result should appear is selected, then the Sum tool is chosen, and after that the user has to select the cells in which the sum should be calculated. The result appears in the cell selected at the beginning.
Alternatively, the user selects the cells in which the sum should be calculated and then chooses the Sum tool. If there is one row, the result appears after it. If multiple rows are selected, the minimum of each column appears under each column. The sum of each row can be calculated by holding Shift when the Sum tool is chosen. The results appear after each of the rows.