can Excel convert letter grades to numbers?

I’m trying to fake my way though figuring out how to get Excel to figure out my grades for me this semester - clearly taking a chance with my sanity and my students’ futures. I think I can figure out how to get the spreadsheet to weight and then calculate the averages. But can I enter a conversion scheme someplace and then simply enter letter grades and have Excel convert them all to numeric equivalents, so that it can then do the calculations? And can I get it to do the reverse - once it has calculated a numeric average of these weighted grades, to then convert it back to a letter grade?

Yes. Check out the lookup function.

Yes. I asked that question right here on the boards last year.

Here’s the thread

Also, as i noted in the other thread, this guy explains how it works, and also has a sample spreadsheet that you can download.