1, and >; Number (lowest addend).

2. and

3. Difference > number (minimum minuend) (maximum minuend).

4. Poor; poor

Add, subtract and enclose jingles:

Parentheses, the key is to look at symbols.

There is a plus sign in front of the brackets, and the brackets remain unchanged.

There is a minus sign in front of the brackets, which will change when the brackets are deleted and added.

Law of addition:

One-digit addition: when two one-digit numbers are added, the sum can be obtained directly by counting, and the result of adding two one-digit numbers is usually compiled into an addition table.

Multi-digit addition: add the numbers on the same digit, which digit adds up to ten, and then enter one to the previous digit.

Multiple digits plus multiple digits, two multiple digits can be written as the sum of different counting units, and then the numbers of the same counting unit are added respectively according to the addition algorithm and the addition rule of one digit.

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:

Qu kuohao

1, when the plus sign is in front of the bracket, remove the bracket, and the formula in the bracket remains unchanged.

For example: 3+(6-4)=3+6-4

2. When there is a minus sign in front of the bracket, remove the bracket, and the plus sign in the bracket becomes a minus sign, and the minus sign becomes a plus sign.

For example: 4-(5-3+8)=4-5+3-8

3. When deleting brackets, the symbol before brackets should be deleted together with brackets.

4. At the same time, when the "-"comes before the bracket, all items in the bracket should change their symbols after the bracket is removed. You can't just change the symbol of the first item or the first few items in brackets and forget to change the rest of the symbols.

Simple formula for adding and subtracting brackets

The mixed problem of addition and subtraction with brackets is simple and easy to calculate;

Remove the brackets first, then use the commutative law and associative law of addition.

If there is multiplication, it is necessary to use the commutative law and associative law of multiplication for simple calculation.