Which rows did your AI Excel sales total include?

You filter a sales sheet to this month's completed orders, then ask an AI assistant for the total. Before sending the answer to a colleague, ask it to show which rows it counted. The view on your screen is not a complete specification of the calculation. Microsoft's existing Excel guide makes a useful distinction: SUBTOTAL excludes rows removed by a filter. With function number 9 it still includes manually hidden rows; with 109 it excludes those too. Hiding a column does not have the same effect. For a simple vertical amount column, =SUBTOTAL(109,D2:D100) is a way to check the visible-row sum, provided that range covers the intended orders. It is not automatically the right business total: hiding an awkward order should not remove real revenue. Agree whether the report covers all orders, completed orders or only the current view first. I'd ask the assistant to leave the date range, order-status rule and source range beside the total. Then change a filter on a copy and check whether the answer behaves as intended. That is a check I suggest from Excel's documented behavior, not a failure I've reproduced in an AI tool. A correct addition can still answer the wrong question. Making the included orders visible is cheaper than explaining two different sales figures at the next meeting.