I am having trouble, do not really understand LIFO, I highlighted the parts I need help with.

Scrappers Supplies tracks the number of units purchased and sold throughout each accounting period but applies its inventory costing method at the end of each period, as if it uses a periodic inventory system. Assume its accounting records provided the following information at the end of the annual accounting period, December 31. Units 200 Unit Cost $30 Transactions Beginning inventory, January 1 Transactions during the year: a. Purchase on account, March 2 b. Cash sale, April 1 ($46 each) c. Purchase on account, June 30 d. Cash sale, August 1 (546 each) 32 300 (350) 250 (50) 36 Required: 1-a. Calculate the cost of Goods Sold and Ending Inventory for Scrappers Supplies assuming it applies the LIFO cost method perpetually at the time of each sale. TIP: The sale of 350 units on April 1 is assumed, under LIFO, to consist of the 300 units purchased March 2 and 50 units from beginning inventory. LIFO (Perpetual) Units Cost per Total Unit 200 S 30.00 $ 6,000 300 S 32.00 250 S 36.00 550 18,600 24,600 750 Beginning Inventory Purchases March 2 June 30 Total Purchases Goods Available for Sale Cost of Goods Sold Units from beginning inventory Units from March 2 purchase Units from June 30 purchase Total Cost of Goods Sold Ending Inventory 300 S 32.00 S 36.00 300 9,600