一、问题的提出“求相差数”、“求比一个数多几的数”及“求比一个数少几的数”是同一数量关系的三种不同形式(以下统称为差比类应用题)。这类题是简单应用题的重点及难点,教学中常常产生这样的现象:每教一类时,解题正确率很高,综合在一起就容易混淆;刚教学如何辨别时学生较能掌握,过一段时间,错误率就明显增高。其原因在于过去教学存在以下几 First, the issue of “seeking the number of difference,” “a number of a few more than a few” and “a few numbers than a few” is the same number of three different forms (hereinafter referred to as the difference between the application ). This kind of question is the key point and the difficulty of the simple application question, the teaching often produces such a phenomenon: When each class is a class, the problem-solving accuracy is very high, when combined, it is easy to be confused; when the teaching is discerning, After a while, the error rate is significantly higher. The reason is that in the past there are several teaching