Dakota Enterprises had 400 units in process in the blending department at the beginning of the month

Dakota Enterprises had 400 units in process in the blending department at the beginning of the month. During the month, they started an additional 1,800 units in the blending department,and 250 units remained in process at the end of the month. How many units were transferred out of the blending department during the month? Explain how you computed this amount.