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