3 km = 3 000 m = 300 000 cm
2 300 dm = 230 m = 23 dam;
72 hm = 7 200 m= 7 200 000 mm;
230 000 cm = 230 dam=23 hm;
30 m si dam= 3 dam si ??? dam
97 km si 6 dam= 97 000 m + 60 m = 97 060 m
800 mm si 9 cm = 80 cm + 9 cm = 89 cm
42 000 dm si 120 m= 420 dam + 12 dam = 432 dam