北师大版四年级下册数学《街心广场PPT课件》公开课教学备课讲稿.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,第三级,第四级,第五级,绿色圃中小学教育网,*,街心广场,北师大版四年级数学下册,积翠中心校,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,绿色圃中小学教育网,教学目标,本节课我们主要来探索乘数的变化会引起积有什么样的变化？同学们要认真观察看看乘数的小数位数和积的小数位数有什么关系，并且运用这种关系解决实际问题。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,绿色圃中小学教育网,0.3米=3分米 0.2分米=2米,32=6(分米,2,)6分米,2,=0.06米,2,所以0.30.2=0.06(米,2,),Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,绿色圃中小学教育网,4 3 =,你发现了什么?,12,4 0.3=,1.2,0.4 0.3=,0.12,不变,缩小,10倍,缩小,10倍,缩小,10倍,不变,缩小,10倍,13 2 =,0.13 2 =,0.130.2=,26,0.26,0.026,缩小,100倍,不变,缩小,100倍,不变,缩小,10倍,缩小,10倍,一个乘数不变,另一个乘数缩小10倍、100倍积也缩小10倍、100倍,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,绿色圃中小学教育网,4 3 =,12,4 0.3=,1.2,0.4 0.3=,0.12,不变,扩大,10倍,扩大,10倍,扩大,10倍,不变,扩大,10倍,13 2 =,0.13 2 =,0.130.2=,26,0.26,0.026,扩大,100倍,不变,扩大,100倍,不变,扩大,10倍,扩大,10倍,一个乘数不变,另一个乘数缩小10倍、100倍积也缩小10倍、100倍,一个乘数不变,另一个乘数缩小（或扩大）10倍、100倍积也缩小（或扩大）10倍、100倍,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,绿色圃中小学教育网,1 1,2,2 0,2,2 1,3,你又发现了什么?,0,1,1,0.12,0.26,0.026,+,=,+,+,+,=,=,=,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,绿色圃中小学教育网,你知道下列算式的积有几位小数吗?,0.780.3 1.532.25 16.718.2,0.0010.01 150.723 0.050.05,8.64,86.4,86.4,0.864,5.46,0.325,5.7312,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,绿色圃中小学教育网,1911=209,()()=0.209,游戏时间到了!,规则:根据第一道算式和第二个积说出乘法算式,说不出就出局.,0.0209,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,绿色圃中小学教育网,?,0.50.4=0.2,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,绿色圃中小学教育网,请在下面各题中点上小数点。,3.6,3,1,0,8,0.4,0.6,1 2,1.03,0.04,4 1,2,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,绿色圃中小学教育网,想一想 算一算。,2040=,0.20.4=,24=,0.020.04=,绿色圃中小学教育网,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,绿色圃中小学教育网,你会计算这块,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,绿色圃中小学教育网,