I have a large spreadsheet of information that I am trying to simplify by
creating a "group" column. I need to build a formula that will look at the
number value in another cell and return a letter value based upon where
number value falls in my predetermined range.

For example; The formula will be in cell B1. I want to look at the number
value in cell A1. If the value in A1 is 10-50, 80 or 81 I want "F" to appear
in B1. If the value in A1 is 60-69 I want "V" to appear in B1.