If and ifs help

Usually the #Name error indicates there is something wrong with your syntax.  Do you have a non-sensitive copy of your workbook that you could provide or perhaps a few screenshots of the error along with the values.  What does the actual formula look like?

Other Thoughts:

It may be easier to do grades using vlookup rather than an IF statement.  Here's a tutorial to accomplish this: https://exceljet.net/formula/calculate-grades-with-vlookup