Difference between two columns

[Ariz]

Hi all

Please can anyone advise which formula should I use to calculate difference between two columns in a new column.

thanks

Ariz 

[franc1s]

I have a similar question, but, I think it is one step further. For all numeric columns in a table, I am looking for a workflow that calculates the difference between subsequent columns. The number of columns is variable. The difference between known columns is pretty easy, but, I dont know how to make it "dynamic". I would appreciate some help from the community.