3. In lesson 6 you learned that The Associative Property of Addition *
States that three or more numbers being added must be added from left to right
States that three or more numbers being added can be grouped in any way without affecting the sum
States that three or more numbers being added or subtracted can be grouped in any way without affecting the outcome
States that for every number a, there is a number -a such that a + (-a) = 0