a) 153°59' - 38°45' = 115°14'
b) 41°26' - 18°30' = 40°86' - 18°30' = 22°56'
c) 20° - 16°56' = 3°4'
d) 60° : 5° = 12
e) 14°40' × 3 = 42°120' = 44°
f) 86° : 6 = 84°120' : 6 = 14°20'
