Properties of Operations with Real Numbers Property Commutative Property Associative Property Key Idea changing the order of numbers when adding or multiplying changing the numbers grouped in parenthesis without changing the order when adding or multiplying Poem Commute the numbers from place to place. A change in order is what you’ll face. Associate the numbers, that’s all you have to do. Putting them in groups is entirely up to you. Picture Examples Commutative Property of Addition 8 + 3 + 10 = 10 + 8 + 3 Commutative Property of Multiplication 3•x•4=3•4•x Associative Property of Addition (x + 2) + 9 = x + (2 + 9) Associative Property of Multiplication (9 ● 8 ) ● 2 = 9 ● (8 ● 2) Additive Identity Property 4+0=4 Identity Property keeping the number the same; maintaining the number’s identity I look in the mirror and what do I see? The number’s identity staring back at me. (4x + 2 ) + 0 = 4x + 2 Multiplicative Identity Property x●1=x (6x + 3) ● 1 = 6x + 3 Additive Inverse Property 7 + -7 = 0 x + -x = 0 Inverse Property undoing or canceling a number Upside down or inside out, that’s what inverse is all about. Multiplicative Inverse Property 4• • Distributive Property rewriting an expression using multiplication; distribute (pass out/share) the number outside the parentheses to all numbers inside Distribute through the group, each number gets a turn. Multiply then add/subtract to show what you have learned. Multiplicative Property of Zero multiplying by zero; any number times zero equals zero Multiply by zero and see what you get. The answer is zero – on that you can bet. =1 =1 2(3 + 4) = 2(3) + 2(4) 8(x - 5) = 8(x) - 8(5) 3●0=0 m●0=0 (8x + 1) ● 0 = 0 Identifying Properties Identify the property shown by each equation 1. 12 · 32 + 12 · 8 = 12 · (32 + 8) _____________________________________ 2. -19 + 19 = 0 _____________________________________ 3. 1 · (4 + 6) = (4 + 6) · 1 _____________________________________ 4. 97 + (3 + 35) = (97 + 3) + 35 _____________________________________ 5. 0 + (7 · 3) = (7 · 3) _____________________________________ 6. 97 + 3 + 35 = 97 + 35 + 3 _____________________________________ 7. -8 · 1 = 1 · (-8) _____________________________________ 8. 0 + (10 · 3) = (10 · 3) + 0 _____________________________________ 9. 20 · (5 · 87) = (20 · 5) · 87 _____________________________________ 10. (7 · 4) + 6 = 6 + (7 · 4) _____________________________________ 11. (13 + 9) + 0 = 13 + 9 _____________________________________ 12. 48 · 5 + 48 · 15 = 48(5 + 15) _____________________________________ 13. (4 + 14) · 1 = (4 + 14) _____________________________________ 14. (12+ 3) + 5 = (3 + 12) + 5 _____________________________________ 15. 20 · (5 · 87) = 20 · (87 · 5) _____________________________________