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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,#,伊宁市第十四小学,人教新课标四年级数学下册,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,植树问题,人教新课标四年级数学下册,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,教学目标,本节课我们来学习植树问题,同学们要根据生活中的实际例子去探索两棵树的间距,植树的棵树以及总的植树距离之间有怎么样的关系,注意要分两端都植树,一端植树以及两端都不植树等情况进行讨论。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,同学们在全长,20,米的小路,一边,植树,每隔,5,米栽一棵,一共需要多少棵树苗?,设计一份植树方案,并说明理由。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,同学们在全长,20,米的小路,一边,植树,每隔,5,米栽一棵(,两端要栽,)。一共需要多少棵树苗?,20,米,5,米,20 5=4 4+1=5,(棵),答,:,一共需要,5,棵树苗。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,两端都栽的植树问题,棵数,=,间隔数,+1,间隔数,=,棵数,1,全长,间距,=,间隔数,全长,间隔数,=,间距,间隔数,间距,=,全长,(棵数,1),间距,=,全长,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,同学们在全长,20,米的小路,一边,植树,每隔,5,米栽一棵(,两端都不栽,)。一共需要多少棵树苗?,5,米,20,米,20,5=4 4-1=3,(棵),答,:,一共需要,3,棵树苗。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,大象馆和猩猩馆相距,60,米。绿化队要在两馆间的小路两旁栽树,相邻两棵树之间的距离是,3,米。一共要栽几棵树?,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,603=20,(),2,(),20,()(),答:一共要栽 棵树。,1,19,19,38,38,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,一根木头长,10,米,要把它平均分成,5,段。每锯下一段需要,8,分钟,锯完一共要花多少分钟?,5-1=4(,次,)84=32(,分,),答,:,锯完一共要花,32,分钟,.,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,两端都不栽的植树问题,棵数,=,间隔数,1,间隔数,=,棵数,+1,棵数,=,全长,间距,1,全长,=,间距,(棵数,+1,),Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,同学们在全长,20,米的小路,一边,植树,每隔,5,米栽一棵(,只栽一端,)。一共需要多少棵树苗?,205=4(,棵,),答,:,一共需要,3,棵树苗。,20,米,5,米,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,39,路公共汽车行驶路线全长,12,千米,相邻两站的距离是,1,千米,一共有几个车站?,121=12,12+1=13(,个,),答,:,一共有,13,个车站。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,学校教学楼每层楼梯有,24,个台阶,老师从一楼开始一共走了,72,个台阶。老师走到了第几层?,7224=3,3+1=4(,层,),答,:,老师走到了第,4,层。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,走楼梯,每,2,层之间的台阶是,20,个,我上到,5,层,我走了多少个小台阶?,5-1=4,204=80(,个,),答,:,我走了,80,个小台阶。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,园林工人沿公路一侧栽树,每隔,6,米种一棵,一共种了,36,棵。从第,1,棵到最后一棵的距离有多远?,36-1=35(,段,),356=210(,米,),答,:,从第,1,棵到最后一棵的距离有,210,米。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,在一条全长,2,千米的街道两旁安装路灯,(两端也要安装),每隔,50,米安装一座,,一共要安装多少座路灯?,200050=40,40+1=41(,座,),412=82(,座,),答,:,一共要安装,82,座路灯。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,笔直的跑道一旁插着,51,面小旗,,它们的间隔是,2,米,现在要改为只,插,26,面小旗,间隔应改为多少米?,51-1=50(,段,),502=100(,米,),26-1=25(,段,),10025=4(,米,),答,:,间隔应改为,4,米。,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,同学们在全长,20,米的小路一边植树,每隔,5,米栽一棵(两端要栽)。一共需要多少棵树苗?,205,4,这里共有,4,个间隔,所以一共要栽()棵树。,5,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,酒店里的大钟,4,时敲,4,下,,6,秒敲完,,10,时敲响,10,下,需要多长时间?,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,圆形花坛的一周全长,50,米,如果沿着这一圈每隔,2,米摆放一盆花,一共需要多少盆花?,502=25(,盆,),答,:,一共需要,25,盆花。,圆形,:,棵数,=,段数,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,在封闭的线路上种树,棵树,=,间隔数,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,19,19,17,17,192,172,72,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,184,72,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,你还有其它的方法吗?试试看!,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,16,棵,14,棵,12,棵,沿正方形的池塘边植树,要求每边都植,4,棵,一共需要多少棵树苗?,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,(,一)巩固提高题,1,、沿一个正三角形实验田的外边,每边 种,8,棵向日葵最少能种几棵?,2,、,16,名学生在操场上做游戏,围成一个正方形,每边人数相等。四个顶点都有人,每边各有几名学生?若相邻两个同学之间相隔,1,米,围成的正方形的边长是多少米?,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,(二)课后延伸题,1,、“四(,4,)班”召开班会时,同学们围坐在一起,如果每边做,5,人,(如下图),这个班一共有多少个同学?每边都有,5,张课桌,一共要多少张课桌子?,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,2,、公园里的花坛有以下几种形状,请选择一种你最喜欢的形状,计算一下如果每边放,4,盆花,至少一共可以摆放多少盆花?,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,考考你,本节课同学们都学了哪些内容,?,你能画一些简单的示意图来表示植树问题不同情况吗?并写出你的解题的方法。试试看!,Evaluation only.,Created with Aspose.Slides for.NET 3.5 Client Profile 5.2.0.0.,Copyright 2004-2011 Aspose Pty Ltd.,
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