The first step in assigning costs is to determine the number of equivalent units for each cost element and the cost of each equivalent unit. Because fifo costing is used, the cost in beginning inventory is assigned to the first units transferred out, and the cost of each equivalent unit contains only cost added during the current period. As explained in chapter 6, the cost per equivalent unit for each element of cost is determined by dividing the cost added during the current period for each cost element by the number of equivalent units of that cost element added in the current period. The equivalent units of a cost element added in the current period is the sum of the equivalent units required to complete beginning inventory , the equivalent units in the mugs started and completed during the period, and the equivalent units in ending inventory ; the result is the same as the total equivalent units that would have been computed if average costing were used, minus the