This previous post solved my Edit Calculation issue.
Since, many of the students have already completed the course -
I decided to just adjust the weighting on the grade items.
The original gradebook setup had all grade items weights distributed equally = 100.
The students must achieve a passing grade on the first quiz in order to progress to the next course activity.
So I adjusted that weight = 0.
The last quiz, I adjust to double it's original weighted value.
Now the students do not see a Pass grade when they only complete 7 or the required 8 quizzes for the course.