本章是整个代数学习的基础，概念多，难度大同学们在复习时要抓住以下几个要点：一、理解和掌握五个重要概念1有理数的概念和分类．引进了正数和负数（零是唯一的中性数）后，便可确定有理数的概念．整数和分数统称有理数．有理数可作如下两种分类：（工）整分法．（H）三分法 This chapter is the basis of the whole algebra learning. There are many concepts, and it is difficult for students to grasp the following points when reviewing: First, understand and master five important concepts: 1 The concept and classification of rational numbers. After introducing positive and negative numbers (zero is the only neutral number), the concept of rational numbers can be determined. Integers and fractions are collectively called rational numbers. Rational numbers can be classified into the following two categories: (work) integral method. (H) Trichotomy