论文部分内容阅读
比与除法、分数有着密不可分的关系,因此,善于把比的问题转化成相应的乘除法、分数问题,就会有更宽阔的思路。【例1】小元和小方各有贺卡张数的比是5:3,已知小元有100张,求小芳有多少张?方法①小元5份100张,每份100÷5=20张,3份100÷5×3=60(张)方法②利用方程,设小方有x张,100:x=5:3解得x=60方法③由5:3可知小元张数是小方张数的5/3,小元张数(100张)=小方张数×5/3,100÷5/3就是小方的张数。
Than with the division, the score is inextricably linked, therefore, is good at the ratio of the problem into the corresponding multiplication and division, score problems, there will be a broader idea. [Example 1] Small and small parties each has a greeting card number is 5: 3, known to have 100 small, how many Xiaofang? Method ① small yuan 5 100, each 100 ÷ 5 = 20, 3 copies of 100 ÷ 5 × 3 = 60 (Zhang) method ② using the equation, set the small side x, 100: x = 5: 3 solution x = 60 method ③ 5: Number of small square number of 5/3, small number of sheets (100) = small square number × 5 / 3,100 ÷ 5/3 is the small number of sheets.