30 mm = 3 cm 3 m 3 dm 3 km. 6 dm = 600 km 6000 m 60 m 60 cm. 3 m = 30 cm 300 cm 30 km 3 000 km. 6 km = 600 m 600 dm 6 000 m 6 000 cm. 500 cm = 5 m 5 dm 5 mm 50 mm. 3 000 m = 30 km 3 km 300 cm 3 cm. 15 cm = 15 m 150 mm 150 dm 1 km. 4 m 40 dm 4 cm 40 km 40 mm. 8 dm 80 m 80 km 80 cm 800 m. 800 cm 8 m 80 dm 80 cm 80 mm.