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比和比例知识在数学中应用特别广泛。解题时,如果我们能善于观察,抓住题中隐藏的比,往往能化繁为简,化难为易,巧妙求解。一、融通比与分数关系,巧列份数解题同学们都学习过比的知识,都知道比与分数、除法的意义非常相近,所以比与分数可以互相转化。题目1.水果店里西瓜个数与白兰瓜个数的比是7:5。如果每天卖出白兰瓜40个,西瓜50个,若干天后,白兰瓜正好卖完,西瓜还剩36个。水果店里原有西瓜多少个?分析与解:根据条件
Ratio and proportion of knowledge in mathematics is particularly widely used. Solving problems, if we can be good at observation, grasp the hidden problems in the title, often can be complicated, simplification is easy, clever solution. First, the fusion ratio and the relationship between the scores, the number of fractional problems Students have learned than the knowledge, we all know than with the score, the meaning of the division is very similar, so the ratio can be transformed with each other. Title 1 fruit shop watermelon number and the ratio of the number of white melon is 7: 5. If you sell 40 white melon, watermelon 50, a few days later, white melon just sell, watermelon left 36. How many original watermelon fruit shop? Analytical solution: According to the conditions