Lesson 2.1: Properties and Operations

Commutative Property In the sum you can add the numbers in any order. a+b = b+a In the product you can multiply the numbers in any order ab= ba

Associative Property Changing the grouping of numbers in a sum does not change the sum (a+b)+c = (b+c)+a Changing the grouping of the numbers in a product does not change the product (ab)c= a(bc)

Identity Properties The sum of a number and the additive identity (0) is the number a+0=a The product of a number and the multiplicative inverse (1) is the number a·1 = a

Name the Property = (45+25)+12 = (25+45) = (45+25)+12 = 45+(25+12) 48+0= 48

Name the Property (5·4)·3 = (4·5)·3 (5·3)·4 = (5·4)·3 (-5)(1) = -5

Using Properties to Simplify the Expression (x+3)+6 4(8y) (m+5)+9 6(3k) 4 + (x+ -1) (2r)(-5)

Multiplying by a Conversion Factor The Steel Dragon 2000 is the world’s longest roller coaster. Its length is 2711 yards. How long is the roller coaster in feet?

Evaluate the Expression 15(-9)(2) 7· x (6c) 5·9· (-4)

Use a Conversion factor 4 miles to feet 360 seconds to minutes 432 inches to feet