Exchange law: additive commutative law: A+B = B+A; ; Multiplicative commutative law: a× b = b× a. associative law: additive associative law: (a+b)+c = a+(b+c); The law of multiplicative association: (a × b) × c = a × (b × c).

The formulas of commutative law and associative law in grade four are basic concepts in mathematics. Commutative law refers to changing the order of numbers in addition or multiplication, and the result remains the same. These formulas are the basis of mathematical operations, and it is very important for fourth-grade students to master these formulas.