Google Sheets Function: COUNTBLANK
The COUNTBLANK function returns the number of empty cells within the specified range of cells.
Usage:
=COUNTBLANK(range)
Usage Example
In this instance, the COUNTBLANK function should return the number of members who have not made a donation by counting the number of empty cells:

Enter the cell range B2 to B11 in the COUNTBLANK function to count the number of empty cells:
=COUNTBLANK(B2:B11)
