Subtracting a number is equal to adding the reciprocal of this number. The subtraction of rational numbers can be converted into addition. Summarized as "two changes and one constant", that is, subtraction becomes addition, subtraction becomes its inverse, and the minuend remains unchanged. It can be expressed as: A-B = A+(-B).

Brief introduction of rational number

Rational number is the collective name of integer (positive integer, 0, negative integer) and fraction, and it is the set of integer and fraction.

Integers can also be regarded as fractions with a denominator of one. Real numbers that are not rational numbers are called irrational numbers, that is, the fractional part of irrational numbers is infinite cyclic numbers. It is one of the important contents in the field of number and algebra, and it is widely used in real life. It is the basis for continuing to learn real numbers, algebraic expressions, equations, inequalities, rectangular coordinate systems, functions, statistics and other mathematical contents and related disciplines.

The set of rational numbers can be represented by the capital black orthographic symbol Q, but Q does not represent rational numbers. The set of rational numbers and rational numbers are two different concepts. The set of rational numbers is the set of all rational numbers, and rational numbers are all elements in the set of rational numbers.

Rational number subtraction division algorithm

subtraction

Subtracting a number is equivalent to adding the reciprocal of this number, that is, the subtraction of rational numbers is converted into addition.

Division operation

1 divided by a number that is not equal to zero is equal to the reciprocal of this number.

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