Zanzibar Metals utilizes a process costing system with three processing departments--melting, molding, and packaging. It's Melting Department had 500 units in Work in Process inventory at June 1. Ending Work in Process inventory on June 30 consisted of 400 units. Materials are added at the beginning of the process. The beginning costs of materials totaled $900. The cost of materials added during June was $3,960. If the material costs per unit for June was $1.35, how many units would have been completed and transferred out during this period?