本刊分两期刊发杨世明老师组织的同一课题《整式的加减》的四个“同课异构”教学案例,通过不同的教学设计,采用了不同的教学方式,欢迎大家评议、讨论、对比,看哪一种效果好,更吸引学生,吸收率高,抑或各有千秋,各有所长,各有所短.特别是国培班的两节西藏老师的课,让大家对西藏的教学现状有所了解. This journal is divided into two periodicals and issues the same four topics as “Complete additions and deletions” of the same subject “teaching and subtraction” organized by teacher Yang Shiming. Through different teaching designs, different teaching methods are adopted. Everyone is welcome to comment and discuss. Contrast, to see which kind of effect is better, more attractive to students, high absorptivity, or each has its own merits, each has its own strengths, and each has its own shortcomings. In particular, the two classes of Tibetan teachers taught by the national class have taught everyone about teaching in Tibet. The status quo understands.