CÂU 4.5000 + 100 = 51007400 – 400 = 70002000⨯ 3 + 600 = 6600

8000 : 2 + 2000 = 6006000 – (5000 – 1000) = 20006000 – 5000 + 1000 = 20007000 – 3000⨯ 2 = 1000(7000 – 3000)⨯ 2 = 8000