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Warm - Up 999 + 364 = (1000 +364) - 1 = 1363 Use a similar problem-solving strategy to compute the following. Show all of your work. Finished early? 1. 998 + 654 •Take out a colored writing utensil and homework. Staple 2. 500-299 homework in order. •Help a neighbor with these 3. 999+998 problems 1.2 & 1.4 Homework Check Using your colored writing utensil, box in the following two problems to be graded by a neighbor. 1.2 # 57) 15 – b, b = 7 1.4 # 27) 33 – 8 * 3 ÷12 Mathematical Properties 1.7-1.8 Pre-Algebra Properties Property 1. Commutative Property of Addition In words… You can add terms in any order In math… 2+3 = 3+2 2. Commutative You can multiply 3 ∙ 7 = 7 ∙ 3 terms in any Property of order Multiplication Pre-Algebra Properties In words… Property In math… 3. Associative Changing the grouping (9+5)+6 = of terms does not Property of 9+(5+6) change the sum Addition 4. Associative Changing the grouping (5∙10) ∙ 3 = of terms does not Property of 5 ∙(10 ∙ 3) Multiplication change the product Pre-Algebra Properties In words… Property Multiply a number in 5. Distributive front of Property parentheses to all terms inside the parentheses In math… 5(x+2) =5∙x + 5∙2 =5x+10 Name this property! 7∙8=8∙7 Commutative Property of Multiplication Name this property! (2+3)+4 = 2+(3+4) Associative Property of Addition Name this property! 2(x+3) = 2x + 6 Distributive Property Name this property! (2)(3)(4) = (3)(2)(4) Commutative Property of Multiplication Name this property! (2+3) + 4 = (3+2) + 4 Commutative Property of Addition Using the Distributive Property Now let’s try to reverse the distributive property! 5 ( ___ n + ___) 3 5n + 15 = ___ Think! What number was distributed to give us 5n and 15? Using the Distributive Property Now let’s try to reverse the distributive property! 7 1 + ___) 2x 7 + 14x = ___ ( ___ Think! What number was distributed to give us 7 and 14x?