(A) gross profit margin method

Net sales = merchandise sales revenue-sales returns and discounts

Gross profit margin = net sales × gross profit margin

Cost of sales = net sales-gross profit margin = net sales ×( 1- gross profit margin)

Ending inventory cost = beginning inventory cost+current purchase cost-current sales cost.

(2) Retail price method

Cost rate = (initial inventory cost+current purchase cost)/(initial inventory price+current purchase price) × 100%

Ending inventory cost = ending inventory total selling price × cost rate

Current sales cost = initial inventory cost+current procurement cost-ending inventory cost.

Moving weighted average can make management know the balance of inventory in time, and the calculated average unit cost and inventory cost of delivery and balance are objective, but complicated.