2 . A month-end review of the inventory indicates that the proper number of books remains in inventory ( no theft or spoilage ) . Determine the proper number of books and the value of those books using a periodic inventory system and first - in first - out cost flow assumption . Calculate Super's cost of goods sold for the month of January . Please show your work including a schedule with the following headings : Beginning Inventory 5 xX Net Purchase + XX Cost of Goods Available for sale we Ending Inventory vv Cost of Goods sold 5 xX