You can also do this, it does the same thing, but is a little easier to read:
Code:Select Case ave(row)
Case Is >= 90
grade(row) = "A"
Case 80 To 89
grade(row) = "B"
Case 70 To 79
grade(row) = "C"
Case 60 To 69
grade(row) = "D"
Case Else
grade(row) = "F"
End Select
