Mathematically, a rational number is the ratio of an integer a to a nonzero integer b, which is usually written as a/b, so it is also called a fraction. In Greek, it is called λ ο γ ο, which originally means "rational number", but the Chinese translation is inappropriate and gradually becomes "rational number". Real numbers that are not rational numbers are called irrational numbers.

Rational number is a general term for integer (positive integer, 0, negative integer) and fraction. Positive integers and fractions are collectively referred to as positive rational numbers, and negative integers and fractions are collectively referred to as negative rational numbers.

Therefore, the number of rational number sets can be divided into positive rational numbers, negative rational numbers and zero. Since any integer or fraction can be converted into a cyclic decimal, and vice versa, every cyclic decimal can also be converted into an integer or fraction, so a rational number can also be defined as a cyclic decimal.

Extended data

First, the mixed operation steps of rational number multiplication and division method

1, first determine the symbol;

2. Determine the absolute value again;

3. Turn division into multiplication;

4. Find the result with approximate points.

Second, the rational number division rule

Rule 1: dividing by a number that is not equal to 0 is equal to multiplying the reciprocal of this number.

Rule 2: divide two numbers, the same sign is positive and the different sign is negative, and divide by the absolute value; Divide 0 by any number that is not equal to 0 to get 0.

Third, the determination of rational number power sign:

1, any degree of a positive number is a positive number;

2. The odd power of a negative number is negative, and the even power of a negative number is positive.

Fourth, the relationship between opposing forces:

1, the odd power of two numbers that are opposites is the opposite number;

Even two opposite numbers have the same power.

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