adding 3 rows of multiple drilling wells

so right now i have a spreadsheet that looks like this:

well...........monthly production...........column3......column4..........3month prod
101...........6..........................................-.................. -
101...........3..........................................-...................-
101...........4..........................................-.................. -
101...........5..........................................- ................. -
102...........11........................................- ..................-
102...........3..........................................- ..................-
102...........0..........................................- ................. -


i want to add only the first 3 months of production for each well. So i would want cell (2,5) to read 13 and cell (6,5) to read 14. My problem lies in the fact that each well may have as many as 100 months of production etc and i only want the first 3 months.

i'm not too good with macros cause i'm so used to c++. Any help would be greatly appreciated

First off, let's fix your cell naming so you conform to Excel... Columns have letters, rows have numbers... so what you mean (in Excel-speak) are E2 and E6.

Try this formula (put it in E2 and copy it down for the rest of the column):=IF(AND(A2<>A1,A2=A3,A2=A4),SUM(B2:B4),"")

Basically it's saying, if this row is a different well than the last one and is the same as the next two then sum three rows of data. Note this will return a blank for a well w/ less than three rows of data.

thanks so much
works perfectly...just a question, what does the "<>" mean?
Does it mean not equal to?

Correct, not equal to.