Yardly Inc. uses the weighted average method for process costing. The company's only processing department began May with 4,700 units of product in process (65% of the conversion process completed). During May, Yardly started 15,600 units of new product, of which 3,400 units remained in ending inventory (55% of the conversion process completed). If materials are added when the units are 60% complete with respect to conversion, how many equivalent whole units with respect to materials would Yardly Inc. have in May?