1, which is widely used. The discussion of rational numbers in junior high school mathematics lessons is widely used in real life. Fraction, ratio and percentage all belong to the category of rational numbers, and these concepts are widely used in economic, commercial, scientific and other fields.

2. The concept is clear. The concept of rational number in junior middle school mathematics class discussion is relatively simple and easy to understand, which helps students to understand abstract concepts and mathematical ideas in mathematics, and also helps students to form a correct mathematical thinking mode.