Integers include positive integers, 0 and negative integers, such as 1, 0,-1 and so on. Fractions consist of numerator and denominator, such as 1/2, 2/3, etc.

The concept of rational number can be traced back to the ancient Greek mathematician eudoxus's Theory of Proportion, and the earliest definition of rational number can be traced back to the work of German mathematician Stephen.

Rational numbers are widely used in mathematics. For example, rational numbers play an important role in algebra, geometry, trigonometry and other fields. They are an important part of mathematics foundation, and are closely related to integers, decimals and percentages.

Rational numbers are also closely related to real numbers. Real numbers include rational numbers and irrational numbers, and rational numbers are subsets of real numbers. At the same time, there are obvious differences between rational numbers and irrational numbers. For example, an irrational number cannot be expressed as the ratio of two integers.

Characteristics of rational number properties:

1, sequence: positive rational number, negative rational number and zero are arranged in sequence on the number axis. Positive rational numbers include positive integers and fractions, negative rational numbers include negative integers and fractions, and zero is the only neutral number. This sequence makes the rational number have a clear position on the number axis.

2. Closure: The set of rational numbers is closed under addition and multiplication operations. In other words, no matter how we add or multiply rational numbers, the result is still rational numbers. This compactness makes rational numbers convenient and reliable in mathematics and practical applications.

3. Denseness: On the number axis, rational numbers are dense, not discrete. In other words, there are other rational numbers between any two rational numbers. This density makes rational numbers have important application value in some mathematical problems, such as solving approximate solutions of equations.

4. Closure: The set of rational numbers is closed under the operations of addition, subtraction, multiplication and division (except division by 0). That is to say, no matter how we do these operations on these rational numbers, the result is still rational numbers. This compactness makes rational numbers convenient and reliable in mathematics and practical applications.