When a numeric field is selected in a Pivot table fields pane, it automatically moves to the Values category, where it can be used for various calculations like sums or averages.
When you select a field that is a number in a Pivot table fields pane, it will automatically be moved to the Values category. The Values area in a PivotTable is where the actual numerical data is displayed and summarized. This can include sums, averages, counts, and other aggregations of the selected numerical data. When you drag a numeric field into the PivotTable, Excel by default assumes you're looking to perform some sort of calculation or summary with the numbers, which is why it places numeric fields in the Values area.
An example to illustrate this would be if you have a field called 'Sales Amount', once selected, it will appear in the Values area of the PivotTable, which will allow you to perform calculations such as summing up all the sales amounts.
In contrast, non-numeric fields are typically added to the Rows, Columns, or Filters areas, which are used to segment and organize the data rather than summarize it.