Gradebook Final Grade (If/Then)

Hey guys,

I am trying to make an excel gradebook for my class and I am trying to figure out the final grade (i.e: A, B,C,D) based on exam grades. I am new to excel and I understand that if/then statements help with this and I am trying to define 89.99 or greater as an A, 80 to 89.99 as a B, 70 to 79.99 as a C, and otherwise then its a D. So far I have this for my cell but I get the #value! error

=IF(D8>=90, “A”), IF(D8>=80, "B"), IF(D8>=70, "C", "D")

What's exactly wrong with this if/then?

Thanks

Bracket mis-placement

=IF(D8>=90,"A",IF(D8>=80,"B",IF(D8>=70,"C","D")))

Thanks Bob, I figured out the parentheses issue after posting it! I had another quick question regarding my gradebook. I am trying to determine if the students made a consistent A or a Consistent C or D based on their two exam grades. In other words I would like to either display Yes/No in the Consistent A column; if they scored a 90 or above on both exames I want the cell to display a Yes, if not then I want it to display no. This goes the same for the C and D column except only if they score less than an 80 in both exams. How would I go about doing that because I know it involved the use of a and function within the If function.

Is this what you mean?

=IF(IF(C2>=90,"A",IF(C2>=80,"B",IF(C2>=70,"C","D")))=IF(D2>=90,"A",IF(D2>=80,"B",IF(D2>=70,"C","D"))),"Yes","No")