Displaying grade based on value

[reem01]

I have a need to display a grade of a # that is calculated by a set of values. I have attached a basic spreadsheet with what I am looking for. There are 5 ranges of grades, and I want a formula in cell C:1, C:2, and C:3 that looks at the corresponding A:# and then determine where in that grade it falls, and display the corresponding letter reflected in C:5-C:9.

Been racking my brain and searching for a while on this with no luck. I am sure it is fairly simple, but is is not coming to me.

Any help would be appreciated.

Thanks

Mike