用计算器探索规律例10

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,用计算器探索规律,0.0909,0.1818,0.4545,0.2727,0.3636,09,18,27,36,45,例、用计算器计算下面各题。,111 =,211 =,311 =,411 =,511 =,商的规律是：都是循环小数；除数不变，被除数,扩大,2,倍，循环节也扩大,2,倍被除数扩大,3,倍，循环,节也扩大,3,倍,循环节是被除数的,9,倍。,0.5454,0.6363,0.7272,0.8181,不计算，用发现的规律直接写出下面,几题的商。,611 =,711 =,811 =,911 =,让我们一起来总结一下，以后你遇到像,上面这样的有规律的问题时，该怎么解,决呢？,1、先观察题目已经给你的算式，从中总结出,规律。,2、运用自己发现的规律去解决接下来的问题。,21,22.11,222.111,2222.1111,37 =,3.36.7 =,3.3366.7 =,3.333666.7 =,两个因数的位数和等于积的位数，,2,的个数等于,1,的个数，小数点在,2,和,1,的中间。,21,22.11,222.111,2222.1111,根据规律很快写出后两题的结果,22222.11111,222222.111111,37 =,3.36.7 =,3.3366.7 =,3.333666.7 =,3.33336666.7 =,3.3333366666.7 =,444.222,4444.2222,67=42,6.66.7=44.22,6.6666.7=,6.666666.7=,练习,:,用计算器计算前,3,题,直接写出后,3,题的得数,:,1234.56799 =,1234.567918=,1234.567927=,1234.567936=,1234.567945=,1234.567954=,11111.1111,22222.2222,33333.3333,44444.4444,55555.5555,66666.6666,(1)0.101 0.2002 0.30003,0.5000005,(2),9 81,43046721,(3)6.25 2.5 1 _ _ 0.064,(4)7 3.5 1.75 _ _ 0.21875,自主探索,先找出规律,再按规律填数。,0.4,0.875,0.400004,0.4375,0.16,3,6561,