Rational number:
Rational number refers to a number that can be written in fractional form, which is called rational number. Any rational number can be written as a fraction m/n(m, n is an integer, n≠0). Any rational number can be represented on the number axis. Integers and fractions are collectively called rational numbers, including integers and fractions, and can also be expressed as finite decimals or infinite cyclic decimals.
Mathematical terms:
The multiplication rule of rational numbers is the multiplication of two numbers, the same sign is positive, the different sign is negative and the absolute value is multiplied. Multiply any number by 0, and the product is still 0. 2. Two numbers whose product is 1 are reciprocal. Multiply multiple rational numbers and multiply several numbers except 0. When the number of negative factors is even, the product is positive, and when the number of negative factors is odd, the product is negative.
Division of rational number is an incomplete inverse operation of rational number multiplication. The operation of finding another factor by knowing the product of two numbers and one of them is called division. Let A and B be two rational numbers, b≠0, and A divided by B is to find a number X, so that X = A, where X is called the quotient obtained by dividing A by B, which is marked as a÷b, A is called the dividend and B is called the divisor.
Specific steps:
1, two numbers are multiplied, the same sign is positive, the different sign is negative, and the absolute value is multiplied. For example: (-5) × (-3) =+(5x3) =15 (-6) × 4 =-(6x4) =-24.
2, any number multiplied by 0, the product is 0. For example: 0× 1=0
3. Multiply several numbers that are not equal to 0, and the sign of the product is determined by the number of negative factors. When the negative factor is odd, the product is negative; When there are even negative factors, the product is positive. And multiply their absolute values. Example: (-10 )× [-5 ]× (-0.1)× (-6) = the product is positive, while (-4)×(-7)×(-25)= the product is negative.
4. Multiply several numbers. When a factor is 0, the product is 0. For example: 3×(-2)×0=0
5. Two rational numbers whose product is 1 are reciprocal. For example, -3 and-1/3, -3/8 and -8/3. 0 has no reciprocal.
6. If the product of two rational numbers is 1, then one of them is called the reciprocal of the other, and these two rational numbers are also called the reciprocal of each other. For example, 3 and 1/3 are reciprocal, and negative 3/8 and negative 8/3 are reciprocal.