The concept of multiplication and division of rational numbers in the first year of mathematics of people's Education Press In urgent need of brothers and sisters

The concept of multiplication and division of rational numbers in the first year of mathematics of people's Education Press In urgent need of brothers and sisters

Rational number is: integer fractional decimal [including negative number, excluding infinite circular decimal] multiplication rule: multiply two numbers, get positive with the same sign, get negative with different sign, and multiply absolute value, multiply any number with 0, get 0 division rule: divide two numbers, get positive with the same sign, get negative with different sign, and divide absolute value, divide 0 by any number that is not equal to 0, get 0.0 divided by a number that is not 0, It is equal to the reciprocal of this number, 0 cannot be divisor