Commutative Property of Addition
Also called order property of addition. This property means that addends can be added in any order and the sum is always the same.
In lesson 8 we used number bonds in order to break apart mixed numbers, and then reorder the bonds in an expression in order to group terms in an easier way.
Below are two in class examples of first: how we broke down mixed numbers into number bonds, and second: how we used number bonds to simplify an expression.
The following video will show you what happens to terms inside of parenthesis when there is a negative outside of those parenthesis.
Below is a student copy of the common core's Applying the Properties of Operations to Add and Subtract Rational Numbers - Lesson 9.