an explanation to be able to do more problems would be greatly appreciated

REQUIRED: Determine the cost assigned to ending inventory and to cost of goods sold using FIFO. Each yellow cell must include a formula using cell references, EVEN IF THE FORMULA RESULT IS ZERO. \begin{tabular}{|c|c|c|c|c|} \hline \begin{tabular}{|c|c|c|c|} \hline Ending Inventory - Perpetual FIFO: & UnitsinEndingInventory & & Costperunit \\ \hline \end{tabular} & & InventoryBalance \\ \hline \end{tabular}