To sum only cells in a range that are numbers, use the SUMIF function in Excel:

1. Select the cell where you want to display the sum of the numbers, for example, A7.
2. Type the formula
   Code:

   =SUMIF(A1:A6,"<#N/A",A1:A6)

   in the formula bar.
3. Press Enter.

This formula will sum all the cells in the range A1:A6 that are not equal to "#N/A". The result will be displayed in cell A7.

If you have other non-numeric values in the range, you can modify the formula to exclude them as well. For example, if you have blank cells or cells with text in the range, you can use the following formula:

This formula subtracts the sum of the blank cells and cells with text from the total sum of the range.