计算题（简便方法）①12.6×7.6×2.32÷1.9÷1.4÷2.9②6.66×1.2＋3.33×7.6③23.5×5.66－23.4×5.67④1.2÷﹙1.2÷2.3﹚÷﹙2.3÷3.4﹚÷﹙3.4÷4.5﹚

①12.6×7.6×2.32÷1.9÷1.4÷2.9
=12.6/1.4*(7.6/1.9)*(2.32/2.9)
=9*4*0.8
=28.8
②6.66×1.2＋3.33×7.6
=3.33(2.4+7.6)
=3.33*10
=33.3
③23.5×5.66－23.4×5.67
=23.5*5.66-(23.5-0.1)(5.66+0.01)
=23.5*5.66-23.5*5.66-0.235+0.566+0.001
=0.332
④1.2÷﹙1.2÷2.3﹚÷﹙2.3÷3.4﹚÷﹙3.4÷4.5﹚
=1*2.3/(2.3/3.4)/(3.4/4.5)
=3.4/(3.4/4.5)
=4.5