My knowledge of Excel is limited to simple formulas, but I'm trying to start a very basic spreadsheet to track the cost of groceries per week. I attempted a "sum-by-week-number" formula that was entered into SHEET1, cell B3, but it's flawed....I'm unable to resolve it no matter what I try. I can see the forum deals with issues a lot more complex, but I'm hoping someone might consider briefly assisting me with this. I've attached two files that show SHEET1 (formula), and SHEET2 (data entry). Hoping they're readable.