Off-balance-sheet calculation, that is, recursive calculation, is an operation that completely writes out the calculation process, that is, off-balance-sheet vertical calculation. When calculating mixed operations, it is usually to work out an expression step by step (step by step, you can't write an equal sign on the original formula), and the process of each step should be written out. Generally speaking, the equal sign should go forward and not be aligned with the first line. That is, to leave the original calculation.

Addition: the operation of combining two numbers into one number.

Subtraction: the operation of finding the other Jm number when the sum of two addends is known.

Multiplication: the operation of finding the product of two numbers.

1, a number multiplied by an integer, is a simple operation to find the sum of several identical addends.

2. Multiplying a number by a decimal is to find a few tenths, a few percent and a few thousandths of this number.

3. A number multiplied by a fraction is a fraction of this number.

Division: the operation of finding another factor by knowing the product of two factors and one of them.

Matters needing attention in comprehensive calculation formula (four operations):

1. If there is only addition and subtraction or only multiplication and division, it is calculated from left to right. For example, 2+ 1- 1=2, first calculate the number of 2+ 1, and then subtract 1 from the number of 2+ 1.

2. If primary operation and secondary operation exist at the same time, the secondary operation is calculated first.

3. If there are primary, secondary and tertiary operations (i.e. power, root and logarithm operations) at the same time, first calculate the tertiary operation, and then calculate the other two levels.

4. If there are brackets, count the numbers in brackets first (no matter what level, count first).

5. The third level should be counted in brackets, and then the second and first levels should be counted.

Extended data:

In an expression, if both first-level operation and second-level operation are included, then the second-level operation should be calculated first, and then the first-level operation should be calculated. That is, "multiply first and then divide, then add and subtract", or "multiply first and then divide, then add and subtract" for short.

Peer operation In an expression, if it only contains peer operation, it should be operated from left to right. That is to say, only addition and subtraction, or only multiplication and division are mixed operations, and their operation order is calculated from left to right.

If you want to change the order of the operations mentioned above, you need to use parentheses. There are three kinds of brackets commonly used: parentheses, marked as (); Parentheses, marked as [; Braces, marked {}. When using the bracket, pull on both sides and add in the middle. Use parentheses first, then brackets, and finally braces.

Baidu Encyclopedia-Offline Computing