小学数学小学四年级《小数的意义PPT》.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,*,第一课时：小数的意义,讲课教师 郭燕,班级：四（,4,）班,请动小手量一量,进行测量和计算时，往往,不能正好得到整数的结果,，这时常用小数或分数来表示。,教学目标,1,使同学们了解小数的产生。,2,使同学们理解小数的意义。,3,掌握小数的计数单位及单位间的进率。,一位小数的改写,1,dm,10,1,m,0,.,1,m,3,dm,10,3,m,0,.,3,m,7,dm,10,7,m,0,.,7,m,小结：,分母是,10,的分数可以写成,一位小数。,巩固练习：,0,.,6,0,.,7,10,7,分数：,小数,：,10,6,两位小数的改写,小结：,分母是,100,的分数可以写成,两位小数。,1c,m,100,1,m,0.01,m,8cm,100,8,m,0,.08m,4cm,100,4,m,0,.04m,0,.,32,100,32,巩固练习：,分数,：,小数,：,三位小数的改写,小结：,分母是,1000,的分数可以写成,三位小数。,1m,m,1000,1,m,0.001,m,6mm,1000,6,m,0.006,m,13mm,1000,13,m,0.013,m,100,1,0.01,100,4,0.04,100,8,0.08,10,1,0.1,10,3,0.3,10,7,0.7,1000,1,0.001,1000,6,0.006,1000,13,0.013,一位小数,的计数单位是十分之一,写作：,0.1,两位小数,的计数单位是百分之一写作：,0.01,三位小数,的计数单位是千分之一写作：,0.001,小数的计数单位,小数的计数单位是十分之一、百分之一、千分之一,分别写作,0.1,、,0.01,、,0.001,1 0.1 0.01 0.001,1,米,1,米,米,1,分米,10,1,米,米,1,厘米,100,1,米,米,1,毫米,1000,1,米,米,0.1,0.01,0.001,(),个,(),个,10,10,1,(),个,10,（五）小数相邻两个计数单位间的进率,绿色圃中小学教育网,小数中，每相邻两个计数单位间的进率是,10,。,绿色圃中小学教育网,小 结,小数的,计数单位,是十分之一、百分之一、千分之一,分别写作,0.1,、,0.01,、,0.001,每相邻两个计数单位间的,进率是,10,。,在进行测量和计算时，往往,不能正好得到整数,的结果，这时常用,小数,来表示：,十分之几,写成,一,位小数，,百分之几,写成,两,位小数，,千分之几,写成,三,位小数,巩固练习,：,教材,36,页练习九第,1,，,2,，,4,，,7,，,8,，,9,题,