You can avoid multiple nested-IF statements by putting those pass grades in a column somewhere (eg X1 to X10). Then you could use this formula:

=IF(ISNA(MATCH(A2,$X$1:$X$10,0)),0,1)

which will return 0 or 1 (which can then be SUMmed quite easily), or you can change these to FALSE and TRUE respectively.

Hope this helps.

Pete