SUM is the spreadsheet equivalent of an open invite: it welcomes everything into the total, whether it belongs there or not.

Under Use function:, choose Sum, which is the default. Notice there are several options you could choose other than SUM. Under Add subtotal to:, choose BUDGET since this is what we want totaled for ...

Every Excel expert knows how to navigate without a mouse and how to format data using keyboard shortcuts. But do you know how to insert a sum without typing the formula?