8 x 15 cm = 15 x 39 km = 81 mm: 9 = 56 hm: 8 = 870 dam + 539 dam - 145 dam = 6 043 mm -1 342 mm + 27 mm = 25 km x 75 + 1 307 km - 493 km = 2 700 dm - 15 dm x 49 + 12 dm x 36 = 840 cm - 72 cm : 8-34 x 12 cm + 56 cm : 7 = 853 m + 81 m: 9 - 12 m: 4 x 156 =