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《江苏教育》(小学版)1993年第6期数学教学一得录“稍复杂的分数应用题解法一议”一文,从“抓住不变量”和“采用‘转化—对比’的方法”两个方面谈引导学生“弄清题中数量关系,从中寻求解题途径”的方法。拜读后颇有收益,启发较大,但又觉意尤未尽,对于一些稍复杂的分数应用题,我想如果能适时地引导学生用“假设”的数学思想解题,则也能收到较好的效果,本文就此谈一点想法,算是对原文的一点补充。例1(原文例4),某粮站运进大米和面粉共8600千克。在售出大米的2/5和面粉的1/3后,还剩5400千克。问该粮店运进大米和面粉各多少?
“Jiangsu Education” (elementary school edition) in 1993 sixth issue of mathematics teaching a “slightly complicated fractional application of a solution to a discussion,” a text, from “seize the invariants” and “using the” transformation - comparison “approach On the aspects to guide students to ”clarify the relationship between the number of questions, from which to find ways to solve problems“ approach. After reading quite profitable, inspired a lot, but also feel particularly unpleasant, for some of the more complicated score application questions, I think if you can guide students in a timely manner with ”hypothetical" mathematical thinking, you can also receive Better results, this article on this idea, be regarded as a little supplementary to the original. Example 1 (the original case 4), a grain station transported a total of 8,600 kilograms of rice and flour. After the sale of 2/5 of rice and 1/3 of the flour, 5400 kg left. Asked the foodstuffs shipped into the rice and flour, how much?