2. Two-stage operation, first multiply and then divide, then add and subtract.

3. When there are brackets, count the inside of brackets first, and then count the outside of brackets.

4. When there are multiple brackets, count the brackets first, then the brackets inside, then the braces inside, and finally the brackets outside.

5. If there is a power, calculate the power first.

6. In the mixed operation, the numbers in parentheses are calculated first, and the parentheses are from small to large. If there is a power, calculate the power first, and then from high to low.

Extended data

Algebraic expression law

1, single polynomial

Multiplying polynomial with monomial means multiplying each term of polynomial by monomial according to the distribution law, and then adding the products.

Note: the result of polynomial multiplying by monomial is still polynomial, and the number of terms is exactly the same as that before multiplication.

2. Polynomial rule

Polynomial multiplication rule: (a+b)(m+n)=am+an+bm+bn(a, b, m, n are all monomials).

(a+b)？ =a？ +b？ +2ab

(a-b)? =a？ +b？ -2ab

References:

Baidu encyclopedia-multiplication rule

References:

Baidu encyclopedia-elementary arithmetic