长方体和正方体表面积的变化(好用)教学提纲.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,*,表面积的变化,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,这是一个棱长是1厘米的正方体的小积木块，它的体积是多少？表面积是多少？,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,探究一,当相同的正方体拼在一起的时候，这里重叠的地方就把它叫做,接缝,，重叠部分的面积就叫做,接缝处的面积,。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,用两个体积是1立方厘米的正方体拼成一个长方体，,体积,有没有变化？,探究一,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,比较拼成的长方体的表面积与原来两个正方体的表面积的和，你有什么发现？,减少2平方厘米,减少2平方厘米,有1条接缝，就是少了,原来两个面的面积,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,用3个这样的正方体拼成一个长方体，表面积比原来减少几个正方形面的面积？,减少2个面,减少2个面,有2,条接缝，就是少了,原来,4,个面的面积,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,用4个这样的正方体拼成一个长方体，表面积比原来减少几个正方形面的面积？,减少2个面,减少2个面,减少2个面,有3,条接缝，就是少了,原来,6,个面的面积,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,减少2个面,减少2个面,减少2个面,减少2个面,减少2个面,正方体的个数,2,3,4,5,拼成后减少了几个面的面积,2,原来正方体一共有几个面,12,你能从表中发现什么？,18,4,24,6,30,8,n,6n,2（n-1,）,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,用下面的两个长方体拼成,一个,长方体，你有什么发现？,5cm,4cm,3cm,5cm,4cm,3cm,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,用下面的两个长方体拼成,一个,长方体，你有什么发现？,5cm,4cm,3cm,5cm,4cm,3cm,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,用下面的两个长方体拼成,一个,长方体，你有什么发现？,5cm,4cm,3cm,5cm,4cm,3cm,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,用下面的两个长方体拼成,一个,长方体，你有什么发现？,5cm,4cm,3cm,5cm,4cm,3cm,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,用下面的两个长方体拼成,一个,长方体，你有什么发现？,5cm,4cm,3cm,5cm,4cm,3cm,都,有,1条接缝，就是少了,原来两个面的面积,54,2,53,2,34,2,表面积最小,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,用6个体积是1立方厘米的正方体可以拼成不同的长方体（如下图）。,哪个长方体的,表,面积大？大多少？,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,