=IF(A115,"A",IF(A113,"B",IF(A111,"C",IF(A19,"D ",IF(A1<10,"F",0)))))

You could try something like this, it looks at cell A1 and if the cell is
15 it assigns and A, if it is 13 it assigns a B, etc.

The actual look of your formula will depend on what letters you are
assigning to which numbers and how many letters you have.

"Giggles" wrote:

I have a spreadsheet that keeps attendance. Now I need to calculate the
units (1 unit= 15 minutes) the children are actual here. On a normal
schedule they are here for 16 units but if the are late the units get
subtracted. When entering the data, they would like to use letter instead of
numbers. Is this possible?