①8.54÷2.8×5.6
②11.7÷(3.8-1.2)
③4.2÷0.75÷0.5
④1.8-0.8÷0.5
⑤2.4÷2.5×4
⑥4.2÷(0.75÷0.5)
①8.65×1.2+1.35×1.2
②5.6×1.25
③2.5×(4+0.6)
④21.6×99+21.6
⑤1.56×101
⑥7.5×1.25×2×8