2. Multiplication and association law: when three numbers are multiplied, the first two numbers are multiplied first and then multiplied, or the last two numbers are multiplied first and then multiplied, and the product is unchanged; (ab)c=a(bc)、(a b) c=a (b c).
3. Multiplication and exchange law: when two numbers are multiplied, the position of the exchange factor remains unchanged; a×b=bxa .
4. The law of addition and association: when three numbers are added, the first two numbers are added first, or the last two numbers are added first, and the sum is unchanged; a+b+c=a+(b+c).
5. additive commutative law: two addends are added, the position of the addend is exchanged, and the sum is unchanged; a+b=b+a，a+c=c+a .
Extended data:
Multiplication association law can change the operation order in multiplication operation? In our daily life, the application of multiplicative associative law is not extensive, and it mainly plays a simple role in some complex operations.
The multiplicative commutative law is generally calculated from left to right in the formula calculation with only multiplication. Sometimes, it can be used for simple operations. As long as the position of the operator has not changed, its operation order will not affect the calculated value.