《分数的初步认识》比较大小.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,*,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,*,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,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,*,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,*,李 芳,石河子第二十一中学,几分之一,人教版数学三年级上册第八单元,分数的初步认识,几分之一,分 数,分数是怎样产生的？,它们各表示什么意思？,怎样读？怎样写？,分数如何比较大小？,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,把一块月饼平均分成,2,份，,二分之一，,每份是这块月饼的一半，也就是它的,二分之一，写作 。,1,2,写作 。,1,2,探 究 新 知,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,1,2,探 究 新 知,1,2,拿出一张长方形纸，先折一折，把它的 涂上颜色。,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,错,状元成才路,状元成才路,状元成才路,状元成才路,涂色部分是不是它们的 呢,?,请大家用手势判断“对”或“错”，,对,对,错,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,分一分，认一认。,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,把一块月饼平均分成,4,份，每份是它的（）分之一，写作 。,1,（）,四,4,分一分，认一认。,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,二分之一,四分之一,三分之一,五分之一,1,4,1,2,1,3,1,5,像这样的数，,都是分数。,学 习 新 知,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,了,解分数各部分名称,读作：,三分之一,1,3,分数线,分子,分母,同学们，你们知道吗，分数的每一部分都有名字。让我们一起来认识一下吧！,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,拿一张正方形纸折一折，表示出它的 。,1,4,我是这样折的。,我这样折！,拿一张正方形纸，先折一折，把它的 涂上你喜欢的颜色。,正方形的四种折法,要想得到谁的几分之一，就必须平均分谁，,同时得到的分数就是对谁而说的,。,乌克兰,波兰,俄罗斯,巴拿马,德国,毛里求斯,欣赏世界各国国旗,1 5,五角星,五角星,1 10,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,下,面哪个图形中的阴影部分可以用 表示？（是的画,“,”,，不是的,画,“,x,”,）,1,4,x,运 用 新 知,(,),(),(),(),(),(),用分数表示各图形的涂色部分,3,1,5,6,1,1,(),(),4,1,八戒，把,1,个,平均分给你和猴哥，,可以怎样分？,猴哥和猪八戒在一次吃西瓜的时候，也想用我们今天学习的分数，它们都想吃的多猴哥想：“我要吃这个西瓜的。”八戒想：“我肚皮大，吃的多，要吃这个西瓜的。”,它们俩谁吃的多？为什么？,思 考？,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,1,9,1,7,1,5,1,3,1,2,1,6,1,4,1,8,”或“,在古代，人们在分东西,时，经常出现不是整数的情,况，于是渐渐产生了分数。,在我国，很早就有了,分数，最初用算筹表示，,比如 就表示成 。,2,1,后来，印度人发明了数字，,用和我国相似的方法表示,再往后，阿拉伯人发明了,分数，把 表示成,2,1,2,1,分数线，就把分数表示成,2,1,课堂小结,布 置 作 业,1,、寻找生活中还有哪些地方可以用分,数表示，说给自己的爸爸、妈妈听。,2,、请你用学具表示出 、。,1,3,1,8,谢谢！再见！,