Properly formatting your Excel models is important because it makes it easier for others to read and understand your analysis… and for you to read and understand it if and when you change it later on. There are universal standards for certain formatting points – such as color coding formulas vs.
Excel Tips
Here is a guided step by step video with each shortcut being pressed. It shows how to type a SUM and select cells from the column automatically using shortcuts, then copy that SUM formula across the row to SUM every column.
Excel Tips
How to solve this error message? There are one or more circular references where a formula refers to its own cell either directly or indirectly