人教社教材初一代数《有理数的减法》是将加法算式和减法算式对比,直观地得出有理数的减法法则的。后面的例题是根据这个法则将减法计算转化为加法计算。教材这样编排是考虑到学生先学习的是有理数的加法,后学习的是减法,将减法计算变为加法计算,以帮助学生把未知化为已知,实现知识的迁移,从而将加减法统一起来。但在实际教学中学生常常会死套法则,将小学里 The first-generation number of textbooks for humane education is “subtraction of rational numbers.” It compares the addition formula with the subtraction formula, and intuitively draws the subtraction rule of rational numbers. The following example is based on this rule to convert subtraction calculations into additions. The textbooks are organized in such a way that the students learn first is the addition of rational numbers, the latter learns the subtraction, and the subtraction calculations become addition calculations to help the students turn the unknowns into known and realize the knowledge transfer, thus the addition and subtraction are unified. stand up. However, in practical teaching, students often die