Combing 2 input values under one column
I would like to add up the 2 input values from "Sales" and "Marketing" into the new column called "Sales and Marketing".
The reason is because there has been a change in the categories of business and the previously separated "Sales" and "Marketing" are now combined as one single category "Sales and Marketing".
Is there a way to add up the 2 figures whilst still maintaining the "input" functionality of the cell? It would not be a ideal situation if I would need to have the users re-enter the values under the new column?