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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,*,循环小数,制作:谭红根,29,0.222,512,0.4166,955,0.16363,商的小数部分,从第三位起,一个数字依次不断的重复出现。,商的小数部分,从第二位起,两个数字依次不断的重复出现。,商的小数部分,从第一位起,一个数字依次不断的重复出现。,判断,1,、,0.8888,是循环小数。,(),2,、,0.1555,是循环小数。,(),3,、,1.2,是循环小数。,(),0.85454,如:,0.85454,保留两位小数,就是:,0.85,0.666,1.48383,4.2525,0.1875875,3.1415926,0.547745,是,是,是,不是,不是,不是,数学万花筒,一个循环小数依次不断重复出现的数字,叫作这个循环小数的,循环节,。,0.666,1.48383,4.2525,0.222,25.4166,0.16363,0.,6,66,1.4,83,83,0.,2,22,25.41,6,6,0.1,63,63,没有循环节,循环小数可以只写一个循环节,并在首位和末位上点两个圆点。,例如:,3.2727,写作,3.,27,0.1875875,写作,0.1,875,读作,三点二七,二七循环,读作,零点一八七五,八七五循环,你能根据下面的商,很快写出结果吗?,111=,0.09,911=,511=,711=,811=,611=,211=,0.18,311=,0.27,411=,0.36,0.45,0.54,0.63,0.72,0.81,笑笑说:“我知道 用四舍,五入法保留四位小数约,是,0.2615,。”,0.2615,她说对了吗,?,0.2615,6,15,0.2616,求下面循环小数的近似数,(,保留三位小数)。,1.29090 0.0183,0.4444 7.2756,1.291,0.018,0.444,7.276,比较大小,0.330.3 1.231.233,1.451.45,8.736736,的小数部分第,19,位上的数字是多少?,谢谢指导,郑叶芳 2007.5,
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