Question: Repeating a formula
I have a spread sheet going for an entire month and I am trying to add two columns and input the SUM in another. I can do this with no problem. Looking to see if I can save time if there is and easier way to do this vs going toe by row inputting this formula. Granted it changes slightly each line. Example: SUM(C15:D15), then the next row is SUM(C16:D16). And so on and so forth. I have looked for an answer everywhere. Please help. I would imagine this is an easy answer for a perfesional user.