Properties of Addition	Rounding to 10	Round to 100	Adding rounded numbers	Vocabulary
100 Associative Property Associative Property What is the property of this example? (3 + 2) +1 = 6	100 20 Round 25 to ten	100 100 Round 123	100 340 Round to 10 112 + 234 =	100 parentheses parentheses States that the sum of any number and zero is the number
200 Associative and Identity property What are the two properties of this example? (3 + 1) + 0 =4	200 50 Round 53	200 200 Round 234	200 800 Round to 100 234 + 567=	200 estimate states that the way addends are grouped does not change the sum
300 Identity Property What is the property of this example? 3 + 0 = 3	300 130 Round 126	300 1, 200 Round 1, 234	300 regroup regroup Symbols which show grouping
400 Communative Property What is the property of this example? 3 + 2 =5 2 + 3 = 5	400 250 Round2 53	400 2, 400 Round 2, 398	400 Mental Math Adding numbers in your head
500 Communative and Identity Property What are the two properties of this example? 9 + 0 = 9 0 + 9 = 9	500 330 Round 333	500 9, 300 Round 9,345

Ch. 2 Math

How many teams are playing ?
Time given to answer each question ?