I am having trouble with subtotaling in Excel. I'm having trouble finding a
way to clearly describe the problem, so I'll just give a very simple example:

I have two columns, one is "Letter" and the other is "Number." I put
letters in the "Letter" column and put various numbers in the "Number" column
to correspond with them. But then I add numbers that don't have a letter
associated with them. For example,
Letter Number
A 3
B 5
B 1
3
A 1
C 6
A 4
C 2
1
4

I sort the worksheet so that all A's are grouped together, all B's are
together, all C's are together, and all of the numbers without a
corresponding letter are together. However, once I go to do a subtotal, the
numbers without a corresponding letter are included in the subtotal for C
(since C is the last header listed when sorted).

Why is it grouping the undesignated group with C? Is there any way to get
it to do subtotals for A, B, C, and the undesignated group separately?