Rational number summary and problems in thinking 1. In the operation of rational number, the operation includes: addition (); the order of the mixed operation of multiplication () is () 2. In the mixed operation of multiplication and division, first () and determine (), and then (), so as to avoid mistakes in () operation. 3. In the addition and subtraction operation, the numbers whose sum is () or () are added respectively, which can simplify the operation and simplify the operation

Rational number summary and problems in thinking 1. In the operation of rational number, the operation includes: addition (); the order of the mixed operation of multiplication () is () 2. In the mixed operation of multiplication and division, first () and determine (), and then (), so as to avoid mistakes in () operation. 3. In the addition and subtraction operation, the numbers whose sum is () or () are added respectively, which can simplify the operation and simplify the operation

1. In the operation of rational number, the operation includes: addition (commutative law); multiplication (commutative law and multiplication combination law). The order of mixed operation (first multiplication and division, then addition and subtraction). 2. In the mixed operation of multiplication and division, first (convert to algebraic expression), and then determine (the number of negative factors), and then (convert divisor to factor), which can (reduce) the errors in the operation, Add the numbers whose sum is (positive) or (negative) respectively to simplify the operation