简便运算及答案.ppt

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1、一、用简便方法计算下面各题：48.7+5.6+11.343.21+98.76+56.79+1.245.48+3.996.3+15.4+0.09+3.7+14.656.8+22.834.65－0.99－0.9734.5－2.9845.7－10.457.3－27.8=48.7+11.3+5.6=60+5.6=65.6=(43.21+56.79)+(98.76+1.24)=100+100=200=5.48+(4－0.01)=5.48+4－0.01=9.47=(6.3+3.7)+(14.6+15.4)+0.09=40+0.09=4

2、0.09=56.8+23－0.2=79.8－0.2=79.6=34.65－1－1+(0.01+0.03)=32.65+0.04=32.69=34.5－3+0.02=31.5+0.02=31.52=45.7－10－0.4=35.7－0.4=35.3=57.3－28+0.2=29.3+0.2=29.567.68－7.3－2.73.65－1.28－0.37－1.7719.826－1.173－5.248－3.405130.8－35.9+5.923.97+0.9+6.823.9+6.78－3.931.61－21.27－1.61=67

3、.68－(7.3+2.7)=67.68－10=57.68=3.65－(1.28+0.37)－1.77=3.65－1.65－1.77=0.23=19.826－(1.173+5.248+3.405)=19.826－9.826=10=130.8－(35.9－5.9)=130.8－30=100.8=23.97+1+7－0.3=31.97－0.3=31.67=23.9－3.9+6.78=20+6.78=26.78=31.61－1.61－21.27=30－21.27=8.7327.64－(5.79+1.64)23.12－(10.12－

4、3.67)20.65－(17.1－1.35)32.75+(15.25－10.68)30.16－23.28+15.280.25×4.78×40.98×2.5=27.64－1.64－5.79=26－5.79=20.21=23.12－10.12+3.67=13+3.67=16.67=20.65+1.35－17.1=22－17.1=4.9=32.75+15.25－10.68=48－10.68=37.32=30.16－(23.28－15.28)=30.16－8=22.16=0.25×4×4.78=1×4.78=4.78=(1－0.0

5、2)×2.5=1×2.5－0.02×2.5=2.5－0.05=2.454.52×0.45+5.48×0.4542×3.91.4×99+1.40.25×7×3.61.25×13×1.610.2×0.412.5×12.5×3242×67+4.2×3308.37×16÷8=0.25×7×(4×0.9）=0.25×4×7×0.9=1×7×0.9=6.3=1.25×13×(8×0.2）=1.25×8×13×0.2=10×13×0.2=26=(10+0.2）×0.41=10×0.41+0.2×0.41=4.1+0.082=4.182=

6、(4.52+5.48）×0.45=10×0.45=4.5=42×(4－0.1）=42×4－42×0.1=168－4.2=163.8=1.4×(99+1）=1.4×100=140=2.5×12.5×(8×4）=(2.5×4)×(12.5×8)=10×100=1000=42×67+42×33=42×(67+33）=42×100=4200=8.37×(16÷8）=8.37×2=16.7428.7÷0.35310÷2.5÷411.2÷9.6×2.4560÷(140÷8)5.6×7÷491÷0.1252.38×4.1+5.8×2.3

7、8+0.23828.7×1.6÷28.7=28.7÷(0.7×0.5）=28.7÷0.7÷0.5=41÷0.5=82=310÷(2.5×4）=310÷10=31=11.2÷(9.6÷2.4）=11.2÷4=2.8=560÷140×8=4×8=32=5.6÷4×7=1.4×7=9.8=(91×8)÷(0.125×8）=728÷1=728=2.38×4.1+5.8×2.38+2.38×0.1=2.38×(4.1+5.8+0.1）=2.38×10=23.8=28.7÷28.7×1.6=1×1.6=1.611÷0.25－10÷0.

8、25(80+5.6)÷8=(11－10)÷0.25=1÷0.25=4=80÷8+5.6÷8=10+0.7=10.77.8×(1.001÷0.26)×0.263.5+17.8×99+14.3100×9.5×0.98+9.5×228×11.11+99.99×8=7.8×1.001×(0.26÷0.26)=7