Periodic Inventory Using FIFO, LIFO, and Weighted Average Cost Methods The units of an item available for sale during the year were as follows: average cost method (round per-unit cost to two decimal places and your final answer to the nearest whole dollar). Feedback Vheck My Work a. When the FIFO method is used, costs are included in cost of goods sold in the order in which they were purchased. b. When the LIFO method is used, the cost of the units sold is the cost of the most recent purchases