Understand properties of multiplication and the relationship between multiplication and division. Apply properties of operations as strategies to multiply and divide. Examples: If 6 Ã— 4 = 24 is known, then 4 Ã— 6 = 24 is also known. (Commutative property of multiplication.) 3 Ã— 5 Ã— 2 can be found by 3 Ã— 5 = 15 then 15 Ã— 2 = 30, or by 5 Ã— 2 = 10 then 3 Ã— 10 = 30. (Associative property of multiplication.) Knowing that 8 Ã— 5 = 40 and 8 Ã— 2 = 16, one can find 8 Ã— 7 as 8 Ã— (5 + 2) = (8 Ã— 5) + (8 Ã— 2) = 40 + 16 = 56. (Distributive property.) (Students need not use formal terms for these properties.)
The commutative and associative properties are a whole lot more interesting when you apply them to a mathematical operation that you created!