If the cell is not empty delete its contents. In the list of commands on the left scroll down to the Calculate command select it and then click Add. Select the table cell where you want your result.
Unfortunately this formula would simply add all the numbers to the left of the cell ie.
This time well use the following formula. Depending on the size of your screen you may have to click the Data button first. How to add subtract multiply and divide cells in a Word table. WordPerfect lets you perform spreadsheet calculations on table data.