【数学】北师大版小学数学四年级下册计算题题库讲课讲稿.doc

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1、北师大版小学数学四年级下册计算题题库小数乘法小数加、减法结合律：(a+b)+c=a+(b+c)(a×b)×c=a×(b×c)乘法分配律a×（b+c）=a×b+a×ca×b+a×c=a×（b+c）脱式计算（按照运算顺序）1.14×0.7=4.5×28=7.4×20=6.2×1.4=5.4×2.6=26.8+3.02=6.07-4.993=3.7+2.36=15.4+2.97=10.2-8.75=2.5×1.9×442×1.25×0.086.9＋4.8＋3.10.6＋6.22+3.7825×0.23×0.4（40+0.8）×2.512.5×（0.8+80

2、）30×（1.5+0.1）3.25×23-3.25×130.28×18－8×0.2812.83－(8.45－3.69)　100－(8.7＋5.24)　84.06＋6.47－5.19　5.43+(15.27+30.29)2.8×1.43＋0.572.3×1.4=3.7×1.8=5.2×1.6=3.6×0.8=0.66×1.4=7.3-2.25=3.8+3.54=3.05-2.9=3.1-2.07=12.7+6.58=1.2×0.04×25320×1.25×818.76-3.47-0.535.17-1.8-3.20.4×23×2.50.36×34+0.3

3、6×667.5×2.3+2.5×2.3(1.25－0.125)×84.5×5.2+4.5×4.87.64×2.5-3.64×2.55.03-2.5+0.9622.8-5.23-9.259.29+3.7×6.3 8.02-5.4+0.984.6×57＋0.23×80.42×0.8=0.24×0.19=2.4×1.3=4.5×2.3=0.72×0.27=28-3.56=10-0.81=10-0.36=20-0.92=8-7.089=0.25×21×401.25×21×0.84.02＋5.4＋0.985.17－1.8－3.23.68＋7.56－2.686.

4、3×43+57×6.317.01×9+17.019.71×2.3+7.7×9.71（100-0.4）×2.510×（5.2+12.3）67.2+41.5-71.3910.75+（0.4+9.4）16.23+8.92-7.5650-28.5×1.213.79-9.53+10.5745×1.2=107×4.6=76×0.37=0.28×0.27=0.75×0.42=96.85-85=45.45-45=10-0.41=45-0.45=3.57+3=0.13×25×0.4（24×2.5）×0.0470.8-1.25-1.754.02-3.5+0.984.25

5、-0.83+0.75（2.5－0.25）×0.47.9×10.8－0.8×7.918.76×9.9＋18.76（8+0.8）×12.526×15.7+15.7×241.5+0.68-0.672.8-8.6+5.8420.8-（15.98-3.9）32.5+（5.07+6.1）3.52-（4.6-3.82）5.61×2.9=3.77×1.8=0.02×96=5.22×0.3=9.99×0.89=5.8-3.25=4.8+18.09=10.3+58.7=8.3-4.56=9.03-8.5=12.5×0.35×825×3.1×0.448.14-2.43-7

6、.574×2.3×2.50.5×15.8×0.24.8×7.8＋7.8×0.5227.5×3.7－7.5×3.7（0.8+8）×12.52.5×0.6-1.5×0.62.5×（40-0.4）3.2×0.36-4.80.56＋6.2＋3.7845×21－50×2.15.45+2.65×2.20.65×90+4.25.63×70=75.6×90=80×0.78=8.06×0.04=1.33×8.9=5.94+10.7=12.3+0.85=37.8+3.02=0.704-0.25=10.1-0.55=48×0.5×0.447×50×0.24×6.32×2.

7、512.5×2.5×0.8×40.25×12.8×0.40.93×6+0.93×4（0.4+10）×2.53.25×23-3.25×130.28×18－8×0.281.25×（100+0.8）50.4×1.9-1.872×0.81+10.412.4-4.09×1.33.2×（14.7-7.65）3.76+0.25+0.40.68×0.77=45.6×0.26=9.57×0.21=38×6.75=7.04×7.8=4.1+2.53=5.07-0.8=5.7-0.73=13.18+5.27=5.16+7.9=1.25×26×807.62+2.6+2.38

8、12-0.28-0.720.25×12.9×0.40.25×32×12.53.65×88+3.65×120.