北师大版四年级上册数学运算律复习课件[1]教学内容.ppt

单击此处编辑母版标题样式,*,单击此处编辑母版文本样式,第二级,德国数学家高斯，近代数学奠基者之一，有,“,数学王子,”,之称。,1+2+3+4+96+97+98+99+100=,？,想：,1+100=101,2+99=101,3+98=101,4+96=101,共有,50,组和是,101,的数,=(,1+100),+(2,+,99)+(3,+,98)+.+(50+51),=,101,50,=5050,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,北师大版四年级上册数学,复习运算律,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,运算定律与,性质,运算定律,加法交换律 a+b=b+a,加法结合律（a+b）+c=a+（b+c）,乘法交换律 ab=ba,乘法结合律（ab）c=a（bc）,乘法分配律（a+b）c=ab+ac,运,算性质,减法的性质 a-b-c=a-（b+c）,除法的,性质,a,b,c=a,（b,c）,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,你们认识它们吗？,灰太狼,懒洋洋,沸洋洋,喜洋洋,美洋洋,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,智力大闯关,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,芝麻开门,第一关,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,认真思考做填空,（1）15+b=b+15 这道等式应用的运算律是（）,（2）395+77+105=77+（395+105）运用了（）,（,3,）4195=19（45）这是应用了（）,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,（,4）当一道算式只有加法运算时，考虑是用（）使计算简便；只有减法运算时，考虑用（）；只有除法运算时，考虑用(）；只有乘法运算时，考虑用（）；只有乘加或乘减运算时考虑用（）使计算简便。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,很高兴认识你们，我愿意成为你们的朋友！,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,第二关,.,火眼金睛,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,（1）125（84）,=125 81254,=1000+500,=1500 （）,(2)（100+1)37,=10037+1,=3700+1,=3701 （）,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,你们真棒，我愿意和你们成为朋友！,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,快乐挑战,第二关,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,（,1,）,126+75+125+54=,（,126+54,）,+,（,75+125,）运用了（）。,A,、加法交换律,B,、加法结合律,C,、乘法交换律和结合律,D,、加法交换律和结合律,（,2,）,25,125,4,8=,（,25,4,）,（,125,8,）运用了（）。,A,、乘法交换律,B,、乘法结合律,C,、乘法交换律和结合律,D,、乘法分配律,对号入座（把正确答案的字母填入括号内）,D,C,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,聪明的孩子，我愿意和你们成为朋友！,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,智慧宫殿,第四关,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,46+32+54,简算,25494,2748+2752,（8+80）125,95,99+95,13101,12532,1983763,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,勇敢的孩子，我也愿意和你们成为朋友！,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,今天的这节课，我们复习了那些内容？你有那些收获？还有那些不理解的问题吗？,小结:,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,课堂小结,运算定律有五条，,我们大家要牢记；,简便计算应细心，,看清符号是关键,。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,谢谢指导,!,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,