Thank you for your reply. I wish it was that simple but it doesn't work. It used to work for 2.1.
I can't get it to show anything other than a number grade in the submission feedback page which is where most of my students look. I can get the grade book to show letter grades only.
My question is that this used to work in 2.1 but doesn't in 2.4. Is this now the default method for 2.4 or is it a bug? If it's not, what's the point of setting course grade settings to letter if this only shows in the grade book?