1小数的产生和意义

1、单击页面即可演示,复习引入,10,个一是,10,个十是,10,个百是,整数的计数单位有,，相邻两,个计数单位之间的进率是,把,1,米平均分成,10,份，每份是,米，份是,米,把米平均分成份，每份是,米，份是,米,小数的产生,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,来表示,小数,米,把米平均分成,份,10,1,0,1,10,3,0,3,10,7,0,7,米,米,米,米,米,10,0.0,1,米,100,100,米,米,米,米,米,把米平均分成,份,1,100,3,0.0,3,6,0,06,100,把米平均分成,份,1000,米,米,米,米,米,米

2、,100,0,1,0.00,1,1000,6,0.00,6,1000,13,0.0,13,小数的产生,分,母,是,10,100,1000,的分数可,以用小数表示,0.0,13,10,10,10,1,0,1,3,0,3,7,0,7,一位小数,1,100,0.0,1,3,100,0.0,3,6,100,0.0,6,两位小数,0.0,06,1,1000,0.00,1,6,1000,13,1000,三位小数,0.001,1000,1,0.01,0.3,里面有,个,0.07,里面有,个,0.015,里面有,个,3,7,15,填一填,0.1,10,1,100,1,十分之一,百分之一,千分之一,写作,0.1

3、,0.01,0.001,一位小数,两位小数,三位小数,计,数,单,位,如果有,1000,个格子，请你按要求,完成以下题目,1,把格子总数的,0.1,涂成红色,2,把格子总数的,0.01,涂成蓝色,3,把格子总数的,0.001,涂成黑色,4,观察涂了颜色的格子数，你发现,小数的计数单位之间有什么关系,0.1,100,个,0.01,10,个,0.001,1,个,0.1,0.01,0.001,每相邻两个计数单位的进率是,10,10,10,一位小数表示,两位小数表,示,三位小数表示,十分之几,百分之几,千分之几,填一填,小数的计数单位有,)(,或,)(,0.1,0.01,0.001,十分之一,百分之一

4、,千分之一,0.6,表示,计数单位是,有,个这样的计数单位,十分之六,十分之一,6,填一填,0.9,里面有,个十分之一,9,0.06,里面有,个百分之一,6,0.013,里面有,个千分之一,13,填一填,分数与小数互化,10,5,100,25,1000,25,10,9,0.9,0.72,0.019,0.5,0.25,0.025,100,72,1000,19,看图写出分数和小数,分数,小数,6,10,0.6,分数,小数,32,100,0.32,小数是指比,1,小的数,继续努力,1,米的,是,0.3,米,10,3,继续努力,小数是我国最早提出和使用的。早在公,元三世纪，我国古代数学家刘徽在解决一个,数学难题时就提出了把整数个位以下无法标,出名称的部分称为微数,小数的名称是公元十三世纪我国元代数,字家朱世杰提出的。在十三世纪中我国出现,了低一格表示小数的记法，如把,63.12,写成,_