820 - 5 ⋅ 12 + 40 = 820 - 60 + 40 = 760 + 40 = 800
540 : 18 + 42 = 30 + 42 = 72
38 + 900 : 150 = 38 + 6 = 44
910 : 70 ⋅ 20 = 13 ⋅ 20 = 260
140 ⋅ 7 + 9 ⋅ 800 = 980 + 7200 = 8180
12 ⋅ 80 - 600 : 200 = 960 - 3 = 957