How to number rows, skip blanks and then ...

[pingvin]

Hi,

I have a small problem. I have 3 colums A, B and C.
In col A I have Family serial number. All parts in the same family have the same serial number.
In col B I have sub serial numbers. Each sub part has it's own designated serial number.
In col C I would like Excel to number each row/sub part in the same family. However blank cells should be skipped.

Col A	Col B	Col C
5555
5555	321	1
5555	325	2
5555	549	3
8888
8888	649	1
8888	821	2
2222
2222	183	1
2222	243	2
2222	764	3

<colgroup><col style="width:54pt" span="3" width="72"> </colgroup><tbody>
</tbody>

I have tried this formula IF(A2=A1,C1+1) But the problem is that it doesn't skip blank cells, so it ends up numbering blank cells or generating "FALSE".
I have also tried IF(AND(B1>0,A2=A1),C1+1,"") but neither of the formula does what I would like to.
Can anybody help me with this problem.

 

[steve the fish]

This requires your data starting in row 2, ie the first 5555 in A2, and the data is sorted like in the example. In C2 place this:

=IF(A2=A1,(B2<>"")+IF(ISNUMBER(C1),C1,0),"")

 

[admiral100]

Hi,

Another option :-

C2 =IF(B2="","",N(C1)+1)

 

[pingvin]

Thank you for the help!