One way
Enter the pattern 1, -1, 0, 0 in any row (say Row 1) starting at Col J and
continue over the cells you want to add

then use this formula where you want the result

=SUMPRODUCT(J1:BR1,J7:BR7)

Verify that BR gives you 31 numbers to add (I am not counting 0's)

"japram" wrote:

I HAVE TO ADD THE CELL EG(J7-K7+N7-O7+R7-S7+.....) LIKE THE SAME SERIES ANY
SHORTCUT TO ADD THIS UP TO 31 NOS