I need to create a custom function called LetterGrade that uses two arguments
TotalPossible and TotalPoints based on the following;
If percentage of TotalPoints/TotalPossible is =90% the letter grade should
be an A, etc. When I type the word percentage it shows an error. do I need
to define percentage if so how.

Sorry I am new at this and any help would be appreciated.

Also I need to declare a variable GradePercentage that calculates
TotalPoints/TotalPossible and compare the gradePercentage to letter grade
cutoffs and return appropriate letter grade from lettergrade function.

I would appreciate and help or examples on this that might help.
thank you,
Marcie