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在解应用题时,有时可以根据某些题的特点,改变看问题的方法与角度,将题中某个已知数量转化为与之有关联的另一个数量,从而又可以对某一个问题有新的理解,从中找到解题的新途径。 [例1] 二年级有学生137人,比三年级少26人。三年级有学生多少人? 分析:二年级比三年级少26人,也可以转换成三年级比二年级多26人。解:137+26=163(人) [例2] 小营村有棉田108亩,占全村耕地面积的3/5,全村耕地面积多少亩? 分析:棉田的亩数占全村耕地面积的3/5,可以转换成全村耕地面积是棉田亩数的5/3倍,于是可列式为:108×5/3=180(亩)
In the solution of the problem, sometimes according to some of the characteristics of the question, change the way to see the problem and point of view, the problem of a known amount into a number associated with another, so you can have a problem New understanding, find a new way to solve problems. [Example 1] There are 137 students in second grade, 26 less than third graders. Third grade students how many? Analysis: second grade than the third grade 26 people can also be converted into third grade 26 more than the second grade. Solution: 137 + 26 = 163 (people) [Example 2] There are 108 mu of cotton fields in Xiaoying Village, accounting for 3/5 of the total cultivated land area of the village. Analysis: The area of cultivated land Of the 3/5, can be converted into the village of arable land area is 5/3 times the number of acres of cotton, then formula can be: 108 × 5/3 = 180 (mu)