In Excel how do I convert back from having row and column NUMBERS.
 

For unknown reasons the row and column numbering has changed from say "C7"
and "D10" to "R7C3" and "R10C4", presumanly "R" menas Row and "C" means
Column. When I want to say multiply C7 by 10 with the result reporting in
cell D10, the cell formula becomes: 10*R[-3]C[-1].

I don't care for this system, and I just want to get back to my old system.
How do I do that?

Thank you

Willem Duyvesteyn

This is an easy fix: you may have accidentally changed a setting while
clicking about the menu.

Please click Tools Options General and de-select "R1C1 Style".