inventory count formula

[dreammastah]

I have two columns in a spreadsheet and each one corresponds to a different item. The numbers are the inventory count at the stores. I want to make a formula that will tell me the number of cases needed to send of either item to make them balance out. One SKU is a top, the other is a bottom.

Here is an example of what I mean:

896420     896412
15           6
2            21
9            11

So for each row the formula would ideally tell me the item that needs to be shipped and how many cases I need to balance out with the other one. Each case is packed 12, so if 896420 is 15 and 896412 is 6, I need to ship 1 case of 896412 to then have 15 tops and 18 bottoms, close enough for me. If I need at least 6 pieces (half a case) to balance them out, I'll ship an entire case.

I don't know enough about excel formulas to even start making this one. Please help.

edit: It would be great if the output could put the SKU needed in one column and the amount of cases in the next. I'm going to need to copy/paste this into another spreadsheet to finish this later. Thanks.

edit2: I've got the first part of it that will tell me which SKU needs to be sent, but I don't know how to figure the amount of cases for the next column.

This is what I used

=IF(AND(A2>B2),"896501",IF(AND(A2<B2),"896420",IF(AND(A2=B2),"")))

[mrice]

Something like...

=INT(ABS((A2-B2))/12)+1