a) 9 dam + 60 m = 90 m + 60 m = 150 m
4 hm + 5 dam = 40 dam + 5 dam = 45 dam
9 hm + 63 dam = 90 000 cm + 63 000 cm = 153 000 cm
75 dam + 130 km = 750 m + 130 000 m = 130 750 m
430 m + 60 m = 43 dam + 6 dam = 49 dam
b) 72 dam - 140 m = 720 m - 140 m = 580 m
1870 dam - 21 hm = 187 hm - 21 hm = 166 hm
570 m - 1600 dm = 57000 cm - 16000 cm = 41 000 cm
9 km - 9 hm = 900 dam - 90 dam = 810 dam
630 cm - 120 mm = 6300 mm - 120 mm = 6180 mm
21 km - 18 dam = 210 000 dm - 1800 dm = 208 200 dm
