There are many ways to count numbers in Excel while excluding duplicate values, including using the “Remove Duplicates” feature.
For those who do not know that you can also count values excluding duplicates in a PivotTable, here is how.

- Select the range of data you want to use for the PivotTable.
- When you click the PivotTable button, a box appears where you can choose whether to use the Data Model, as shown below. Select “Add this data to the Data Model.”

3. Then select the field value. Under Value Field Settings, you can find the “Distinct Count” option for counting values while excluding duplicates.
Notes
Distinct Count in a PivotTable may not work depending on the Excel file format.
For example, Distinct Count cannot be applied to files saved in CSV format.
In this case, convert the file to a different format.
Conclusion
As AI advances, individual Excel skills may seem less important. However, to put something into action immediately, you can only work with what you already know, so I believe continued learning is necessary.