title: Sum Google Spreadsheet cells in a certain order
body: <p>I've looked and not been able to get my specific answer. What I'm trying to do is have a total owed cell, and an amount paid cell. I want the total owed to subtract the amount paid, and update itself to the new lesser amount, so that when I enter another amount in the same amount paid cell, it subtracts again from the previously updated amount. I've tried different formulas, but I keep ending up with a circular dependency error. Is there a way to have cells calculate in a certain order? Do cell a21 first, then do cell b21 using the updated value from a21, and so on.</p>