Here is an example:

=SUMIF($AX$3:$CB$3,J$2,$AX6:$CB6)/SUMIF($AX$3:$CB$3,J$2,$AX$5:$CB$5)

The only field that has any data is J$2 (It reads "H")

It is meant to determine the average of homework grades. I have 3 columns of similar formulas, designed to capture HW, CW and Test Averages.

=SUM(AX6:CB6)/D$5

This one is designed to give me the average of all grades.

=Senior!D6

This one reads the previous formula, on a different sheet.

=IF(G5="","",VLOOKUP(G5,'V Lookup'!$A$2:$B$6,2))

This one interprets the =Senior!D6 and turns it into a letter grade.

=SUM(E5,G5,I5,K5,N5)/MAX(1,COUNT(E5,G5,I5,K5,N5))

This one should be creating an average of 4 Marking Period + 1 Final grade, as they are made during the course of the school year.

=E5+G5+I5+K5+N5

This one is summing the 4 MP percentages + Final, as in our district they convert the percentages into points to determine whether a student passes for the year (300 "%" becomes 300 points, thus a pass (60%) for the year).

I am sure that the last several are driven by the second one I recorded for you. I know that I can't work on them until I resolve that one.