Presentation on theme: "Properties of Addition"— Presentation transcript:
1 Properties of Addition To identify addition properties
2 MENTAL MATH Tell me which is greater. 1. 2 + 1 or 2 + 2 ______________
3 Three Properties of Addition Addition properties are likespecial tools.They make it easier to work withnumbers.
4 The Commutative Property BackgroundThe word commutative comes from the verb “to commute.”Definition on dictionary.comCommuting means changing, replacing, or exchangingPeople who travel back and forth to work are called commuters.Traffic Reports given during rush hours are also called commuter reports.
5 Here are two families of commuters. Commuter BCommuter ACommuter A & Commuter B changed lanes.Remember… commute means to change.Commuter ACommuter B
7 Commutative Property You can add in any order. 5 + 2 = 7 * 2 + 5 = 7 5 + 2 = * = 7= * = 16
8 The Associative Property BackgroundThe word associative comes from the verb “to associate.”Definition on dictionary.comAssociate means connected, joined, or relatedPeople who work together are called associates.They are joined together by business, and they do talk to one another.
9 Let’s look at another hypothetical situation Three people work together.Associate B needs to call Associates A and C to share some news.Does it matter who he calls first?
10 Here are three associates. BB calls A firstHe calls C lastACIf he called C first, then called A, would it have made a difference?NO!
11 (The Role of Parentheses) In math, we use parentheses to show groups.In the order of operations, the numbers and operations in parentheses are done first.So….
12 You can change the grouping. Associative PropertyYou can change the grouping.REMEMBER: Add the numbers in parentheses first.* (6 + 3) + 5 = * 6 + (3 + 5) = 14* (8 + 2) + 4 = * 8 + (2 + 4) = 14
13 The Identity Property of Addition I am me!You cannot changeMy identity!
14 Zero is the only number you can add to something and doesn’t change.