Translating a row formula down

[TomCampbell]

Hi, I’m trying to apply a formula down a column. However, I also need to increase the cell number by 1 each time I move down. How do I do this?

etc original formula is =B9+B10. I need the formula beneath it to be B10+B11 etc

[#2]

@TomCampbell 

If you drag the cell with formula down it'll be as you ask. Or you mean something else?

[#3]

@TomCampbellJust a picture to help. The formula in C2 is B2+B3. If you grab the corner of the cell and pull it down the column, it will copy the formula but advance it by one number like you requested. So the formula in C3 is B3+B4, etc.