符号的确定对七年级的学生来说是一件非常头疼的事,稍不留神就容易出错,对八、九年级的学生来说未尝不是这样,如能正确使用“同号为正,异号为负”这一原理,将给学生的学习带来事半功倍之效果,也可达到减负的目的。一、“同号为正,异号为负”在化简符号中的应用在相反数部分,我们知道的相反数是,如果要化简的符号,如相反数的概念掌握不好,化简起来就很不容易,还给七年级的学生加重了学习的负担,如果使用“同号为正,异号为负”这一原理, The symbols are very troublesome to the seventh grade students, so they are easy to make mistakes. For the students in the eighth and ninth grades, this is not the case. Students who use the same characters correctly and correctly Negative number “this principle, will give students more effective learning effects, but also can achieve the purpose of reducing the burden. One, ”the same number is positive, the negative is negative “ in the simplified symbol application In the opposite part, we know the opposite is, if you want to simplify the symbol, such as the concept of the opposite number of mastery is not good, Simplify it is not easy, back to the seventh grade students increased the burden of learning, if you use ”same number as positive, negative sign " this principle,