This part of the extended information mainly examines the knowledge points of elementary arithmetic:

Operation sequence:

When calculating at the same level, it is calculated from left to right in turn.

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

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

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

If there is a power, calculate the power first.

When performing mixed operations, 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.