creating an average for fields within a record

[John Wood]

I am printing a report with each student's letter grades (at this point just for a six weeks grading period)
I would like to include their GPA. I have used a DLookup to convert the letter grades to their numeric equivalent
Note: the grades are listed in a crosstab query, and then brought to the report where text boxes find the numeric equivalent
I can add the number grades, but when I try using AVERAGE, I get a message that the Microsoft Jet database engine does not recognize 'Average' as a field name or expression
It would be nice if everybody had the same number of classes, but this does not happen
And, I wish I could use COUNT for the numeric values, but I don't think I can

I will gladly provide other info if needed, or try for a better explanation
In advance, thank you for any help and advice.

 

[John Wood]

Looking at access help gives me no idea how to use AVG () function.
At this point I have the textboxes (in the report) of E and M (for English and Math) that are numeric.
I expect to (easily) add L, H, S, P and A for the other classes.
Now how do I get an average?
What code do I put in the control source?
=AVG([E],[M]) creates a message about the wrong number of arguments.