“有理数”是初中数学学习的第一章,既是对小学数学负数等知识的进一步深化,也是代数学的重要基础。其实,我们对有理数一点也不陌生,小学学习的整数、分数都是有理数.只不过,把握有理数的核心内涵,需要换一个视角——从辩证的视角准确把握“有理数”这一章中的核心概念(有理数、相反数、绝对值).所谓从辩证的视角把握一个概念,就是说,需要从既对立又统一的关系之中,把握这个概念,而不是孤立地把握这个概念. “Rational Number ” is the first chapter of junior high school mathematics learning, not only deepening knowledge of mathematics such as negative numbers in primary schools, but also an important foundation of algebra. In fact, we are not strangers to rational numbers. Elementary and elementary schools study integers and scores are all rational numbers. However, to grasp the core connotation of rational numbers requires a different perspective - from the dialectical perspective, to accurately grasp the “rational numbers” chapter (Rational number, opposite number, absolute value) .Taking a concept from a dialectical perspective means that we need to grasp this concept from a relationship that is both opposed and unified, rather than holding it in isolation.