In an expression, there are no brackets, only the first stage or only the second stage of operation, which is calculated from left to right in turn; In the expression, there are no brackets.
However, there are both primary operations and secondary operations, so it is necessary to calculate the secondary operation first and then the primary operation, that is, "multiply first and then divide, then add and subtract"; In an operation, there are parentheses, and the inside of the parentheses is counted first; In an expression, there are parentheses, and there are several kinds of parentheses, first in parentheses and then in parentheses.
56+8-6, only the first level operation, calculated from left to right. 56÷8-6 has both primary operation and secondary operation. Calculate the second level first and then the first level, that is, calculate 56 ÷ 8 first and then subtract 6. Of course, because 56÷8 is on the left and "-6" is on the right, its operation order is also calculated from left to right.
Extended data
1 and decimal arithmetic operate in the same order as integer arithmetic.
2. The operation sequence of fractional four operations is the same as that of integer four operations.
3. Mixed operation without brackets:
Operations at the same level are operated from left to right in turn; Two-stage operation calculates multiplication and division first, and then addition and subtraction.
4. Mixed operation with brackets:
Count what is in brackets first, then what is in brackets, and finally what is outside brackets.
Baidu encyclopedia-elementary arithmetic