2.1 Properties and Operations Pre-Algebra Unit 1

Properties A property is something that is true for all situations.

Commutative Property of Addition In a sum, you can add the numbers in any order. A + B = B + A Order doesn’t matter

Commutative Property of Multiplication In a product, you can multiply the numbers in any order. A x B = B x A Order doesn’t matter

Associative Property of Addition Changing the grouping of the numbers in a sum does not change the sum. Associative Property  (a + b) + c = a + (b + c) Example: (6 + 4) + 3 = 6 + (4 + 3) Who’s hangin’ with who?

Associative Property of Multiplication Changing the grouping of the numbers in a product does not change the product. Associative Property  (a · b) · c = a · (b · c) Example: (6 · 4) · 3 = 6 · (4 · 3) Who’s hangin’ with who?

Identity Property of Addition The sum of a number and zero (additive identity), is the number. If you add 0 to any number, the number stays the same.

Identity Property of Multiplications The Product of a number and one (multiplicative identity), is the number. If you multiply any number times 1, the number stays the same.