1. Addition using three addends

2. An associative property is when you group numbers in anyway and the answer stays the same.

3. (10+3)+2=15 same as 10+(3+2)=15 The order of the numbers did not change but the grouping of the numbers changed.

4. (10+3)+2= same as 10+(3+2)= 13 5

5. (10+3)+2= same as 10+(3+2)= 13 +2=15 10 + 5 =15

6. (2+5)+3= 2+(5+3)= 7 8 Remember to add the numbers that are in ( ) parenthesis first. (2+5)+3= 2+(5+3)= 7 +3 =10 2 + 8 =10 Then add the sum of the two numbers to the other number. Changing the grouping of the addends did not change the sums of the problems.

8. (6+3)+4= same as 6+(3+4)= 9 + 4=13 6 + 7 =13 7+(7+3)= (7+7) +3= 7+ 10 =17 14 +3=17