Stoltenberg Co. had the following information for the month of June:

Work in process beginning inventory, June 1	2,000	units
Units transferred in	16,000	units
Work in process ending inventory, June 30	4,000	units

Beginning work-in-process inventory is 30 percent complete as to conversion. Ending work-in-process inventory is 50 percent complete as to conversion. Materials are added at the end of the process. The equivalent units for transferred-in costs under the FIFO method are calculated to be:

(please show step by step for further understanding)