Given lines with amount (positive for income, negative for expenses) in a table called Money, you want to calculate running balance. What should you do?
First you have to define order for lines. Standard Date Create column TeamDesk generates for every table can suit your needs – old lines will appear on top, recent on bottom. If you plan to reorder the lines, you may need to create another, editable Timestamp column, let’s call it Date.
Next, let’s create many-to-many relation from Money table to self, and specify "Date Created < Date Created" match condition (or Date < Date, if you decided for custom timestamp). For any given record this relation will create the list of preceding records. Calculating a total on the amount column will result to opening balance. Adding the total (via formula column) will result to closing balance.
Simple, is not it?