The method of adding serial number in word table: Click Start, find the number and define a new number format. The specific operation is as follows:

In the Word table, select the column cell where you want to insert the serial number. Switch to the "Start" tab, click "Numbering defines a new numbering format", select the required style in the "Numbering Style" in the pop-up window, such as "1, 2,3", and change "1." Go to 1 and Alignment in Number Format. After confirmation, the serial number will be inserted into the selected list cell.

If you want to realize the horizontal serial number in the table, you only need to insert the serial number in each column according to the above method, select the serial number in each column respectively, right-click and select "Continue numbering" to realize the horizontal serial number.

If the serial number of a column to be inserted does not start with "1", such as when inserting the serial number of the third column, it needs to start with "8". At this time, select the column cell that needs serial number, insert serial number as above, right click, select Set Serial Number Value, enter "8" in the "Set Value as" in the pop-up window, and then confirm.

The inserted serial number is not really centered. At this point, you need to select the inserted serial number, right-click and select Adjust list indentation. Set the number position to 0 cm, set it to 0 cm in text indentation, and leave no mark after the number in the pop-up window. Then select all the serial numbers and click the "Center" button, so that the serial numbers are really in the center.