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运用比较思想,认识数量间的关系,从而正确地进行分析、综合和判断推理,有助于寻找解题思路。例1 给小朋友分苹果,如果每人分3个多16个,如果每人分4个要少6个。有多少个苹果?分析解答:由题意可知,小朋友人数和苹果的总个数是不变的。两种分法进行比较,每人分3个同每人分4个相差4-3=1(个),分3个多16个,分4个少6个,相差16+6=22(个)。每人多分1个,要相差22个,这样就知道小朋友人数:(16+6)÷(4-3)=22(人)苹果个数:3×22+16=82(个)。例2 甲、乙、丙三种货物,如果购买甲3件、乙7件、丙1件共花3.15元,如果购买甲4件、乙10
The use of comparative thinking, understanding the relationship between the number, so that the correct analysis, synthesis and judgment of reasoning, help to find ways to solve problems. Example 1 points to the children of apples, if more than 3 points per person 16, if each person points 4 to 6 less. How many apples? Analysis and Answers: By the title we can see that the number of children and the total number of apples is unchanged. Two points for comparison, each divided into 3 with 4 per person difference of 4-3 = 1 (a), divided into 3 more 16, divided into 4 less 6, a difference of 16 +6 = 22 (a ). Each one is divided into 1, to a difference of 22, so you know the number of children: (16 + 6) ÷ (4-3) = 22 (people) Apple number: 3 × 22 +16 = 82 (a). Example 2 A, B, C three kinds of goods, if you buy A 3, B 7, C 1 total spent 3.15 yuan, if you buy a 4, B 10