Like to recommend an approach to designing 'solutions':

- do the hard part first
- solve the problem to get a solution
- then add the presentation of the solution

Steps 1-2 ensure you will complete the problem and if not, you can move on

without investing lots of time in a presentation that goes no where.

Second thought: Separate concepts into separate worksheets.

Attendance is very different from Grading. If there is some values from one

worksheet that needs to be referenced in another there's the style

=worksheet_name!cell_location

=average(worksheet_name!b3:b9)

Excel has a limit of nested functions and nesting even just once per month will still get you into

trouble.

SNGX1275's point on empty cells getting ignored is right on and fits the 'Excel programming model'.

You can infer the **'n'** status from a cell w/o any data. A Cell containing #0 however,

might mean the test has not been taken or sadly, the student scored zero.

I recommend you rethink the problem to be solved and uncouple it from the

presentation.

best wishes.