1. First select the Excel table and double-click to open it.
2. Then, in this interface, select the cell to display the number of non-duplicate companies.
3. Furthermore, in this interface, enter the formula "= SUMPRODUCT (1/COUNTIF (a 1:A6, a1:A6)" in the public notice box to count the number of companies without duplication.
4. Finally, in this interface, non-duplicate company quantity values are displayed in cells.