1000 - 400 · 2 = 1000 - 800 = 200
80 : 2 + 600 = 40 + 600 = 640
30 : 6 · 20 = 5 · 20 = 100
(700 + 13) + 200 = 713 + 200 = 913
(800 + 47) - 500 = 847 - 500 = 347
(400 + 68) + 300 = 468 + 300 = 768
(170 - 110) : 5 = 60 : 5 = 12
(100 - 8) : 4 = 92 : 4 = 23
84 : (230 - 218) = 84 : 12 = 7