Current location - Training Enrollment Network - Mathematics courses - What is the law of mathematical operation in the second volume of the fourth grade?
What is the law of mathematical operation in the second volume of the fourth grade?
The laws of mathematical operations in the second volume of the fourth grade are: additive commutative law, law of addition and association, law of multiplication and exchange, law of multiplication and association, and law of multiplication and distribution.

1, multiplicative distribution law

The most commonly used method in simple calculation is multiplication and distribution law. Multiplication and division means ax(b+c)=axb+axc, where A, B and C are arbitrary real numbers. On the contrary, axb+axc=ax(b+c) is called the inverse application of multiplication and division.

2. Multiplicative associative law

The multiplicative associative law is also a simple method, which is expressed by letters as (a×b)×c=a×(b×c). Its definition (method) is: multiply three numbers, first by the first two numbers, then by the third number; Or multiply the last two numbers first, and then multiply the first number, and the product remains the same.

3. Multiplication and distribution law refers to the sum of two numbers multiplied by one number. You can multiply them by this number first and then add them up. (a+b)×c=a×c+b×c (letter) × c+b× c = (a+b) × c.

4. Multiplicative commutative law

Multiplicative commutative law is used to exchange the positions of various numbers: a× b = b× a.

5. additive commutative law

Additive commutative law is used to exchange various numbers: a+b = b+a.

Application of operation law

The use of algorithms can be a simple formula or a special calculation. It makes use of the algorithm and the basic properties of numbers, which makes the calculation simple and makes it easy to calculate numbers from very complicated formulas.

When performing simple operations (four operations), we should pay attention to the relationship between operation symbols (multiplication, division, addition and subtraction) and big, middle and small brackets. Don't skip the operation to avoid mistakes.