2.5×4×12=0.9×0.8=7.5x-3x=a+3a+7a==1.05×100=1÷0.5=0.96÷3=1.47÷0.7=5.4÷6=0.16.5×10=0.56×100=3.78×100=4÷0.8=3.215×100=0.8×10=4.08×100=1.1×0.2=0.6×0.8=3×0.9=2.5×0.4=3.6×0.4=12.5×8=50×0.04=80×0.3=1.1×9=0.16×5＝1.78＋2.2=9.6÷0.6=1.2×0.5-0.4=0.7÷0.01=2.5×0.4=12－3.9=1.25×8÷1.25=6.6÷0.66=5.37×0+4.63=3.9＋2.03＝4.2÷3.5＝1.6+2.4×0.3=2.14－0.9＝27＋456＋73=0.3×0.3=7.2＋2.8＝0.9÷0.01＝12÷0.3=2.87÷0.7＝13÷4＝0.96÷0.3＝1.5×0.4＝7÷0.25＝2.5×0.7×0.8=8－2.5＝16÷1.6＝5.6×1.01=8×（2.5＋0.25）＝0.36＋0.64＝13.8＋9.9＝2.4×2.5＝0.05×0.8＝2.56－0.37＝1.25×0.8×0.5＝12×2.5＝1.23×3＝3.2÷1.6＝3.5＋3.5×3＝0.75×4＝（1.5＋0.25）×4＝0.5×0.8=8.4×0.2=1.6×0.2＝7.2×0.3=2.8×0.3＝0.9÷0.15=1.8×0.4=5.5÷0.55=0.08×100=2.2÷0.11=5.46＋4.54=12.5×0.8=0.35×0.3=1.4×5=2.8×4=19.6÷4=22.5×4=2、用竖式计算0.04×0.12＝3.84×2.6≈5.76×3＝（保留一位小数）7.15×2290.75÷3.33.68×0.253.7×0.01613.76×0.8=5.2×0.68.4×1.36.4×0.54.48×0.45.25×535.4×4.20.042×0.540.76×0.320.25×0.0462.52×3.41.08×250.12×0.5×0.16＝4.8×0.25＝0.125×1.4≈（保留两位小数）2.5÷0.7=（保留三位小数）10.1÷3.3=（商用循环小数）10.75÷12.5=（用乘法验算）3.25×9.04=（用除法验算）3、脱式计算（能简算的要简算）2.5×7.1×416.12×99＋16.125.2×0.9＋0.97.28×99+7.284.3×50×0.264－2.64×0.526×15.7＋15.7×24(2.275＋0.625)×0.283.94+34.3×0.21.2×(9.6÷2.4)÷4.88.9×1.1×4.72.7×5.4×3.93.6×9.85-5.468.05×3.4+7.66.58×4.5×0.92.8×0.5+1.5832＋4.9－0.94.8－4.8×0.5(1.25－0.125)×84.8×100.156.5×99＋56.57.09×10.8－0.8×7.094.85+0.35÷1.48.7×17.4-8.7×7.412.5×0.4×2.5×80.87×3.16+4.649.5×1010.68÷（5.2-3.5）×1.2540.5÷0.81×0.184.8×（15÷2.4）2．13.×0.×82576.81+6.81×990.25×185×404.4×0.8－3.4×0.8(9.37+9．37+9．37+9．37)×2．54．2.×1.＋1.×1.752.37×6.3+2.37×3.72.5×1.25×0.323.8×10.12.5×(3.8×0.04)7.69×1013.8×10.10.25×39+0.250.125×7246×0.33+54×0.33(8×5.27)×1.256.81+6.81×990.25×185×406.8×0.75÷0.53.75÷0.125–2.751.53+23.4÷7.29.5×9913.5×0.9812.5×8.8二、解方程：54-X=247X=49126÷X=4213+A=28.52.4X=26.47.5x－3x=185×1.3-2x=5.524x+6x=63.65.6x+4.4x=5.2三、列式计算1、20减去0.8的差除以4个0.3的和，商是多少？2、一个数的2.6倍加上9，和