Jenny asks "Is there a quick way of adding every other cell ?, I have a column of about 250 cells, and I have to select them manually using Ctrl. Can you help ?"
Jenny, this is a matter of using a little math to remember how to determine if a number is even or is odd, and then translate that into the formula.
would return 0 if the number is even and 1 if odd. If we use instead of A1, the ROW() function, we can know if a particular row is even or odd. Now, suppose you're trying to calculate this formula
=A1+A3+A5+A7+A9 ... etc.
or this one
Remember, this is a CSE Formula, to enter it you must press at the same time Control Shift Enter, instead of just Enter as regular formulas.
You can also use this non-array formula
By Juan Pablo Gonzalez on 24-Jan-2002