On Aug 13, 6:06 am, Arnold wrote:
Hi Mike,
Your re-wording of my problem is correct. Grades are listed in cols.
AO, AP, AQ, AR... with total possible in row 10 of each col. and
students down col. A.

Your formula works if there is there is a numeric value in AO13 or
AP13. However, it shows #DIV/0! if AO13 is left null.

I tried to redo some of the absolute / relative references to account
for the fact that I only have col. AO right now (through time, AP, AQ,
AR, etc. will be added; we don't know the end of the range though).
However, I got the same #DIV/0! result.

=SUMIF($AO13:AO13,"-.1",$AO13:AO13)/SUMIF($AO13:AO13,"-.1",$AO$10:AO
$10)*100

I think we're close. Any other suggestions? I, and other teachers,
appreciate your help.
Arnold

you could put a simple if then to check if a the denominator of the
equation will be zero, if so return "N/A", otherwise return the score
=IF(SUMIF($AO$13:$AR$13,"-1",$AO$10:$AR$10)=0,"N/A",SUMIF($AO
$13:$AR$13,"-.1",$AO$13:$AR$13)/SUMIF($AO$13:$AR$13,"-1",$AO$10:$AR
$10))

the first part of the equation test the sum if of the total posible
score based on if there is a student score or not. If the total
score, student score or both are blank the sumif will result in 0 and
the logic test will return true. if the total points and the student
have a score -1 the equation will return the sum of the student
scores / total posible. you can substitue any column for AR. the
formula will only use the data if a total posible is entered.