When you are adding two numbers, it doesn't matter which order the numbers are in.
2 + 6 = 8
6 + 2 =8
(Order doesn't matter in addition!)
When solving problems based on the rule from the Order of Operations (PEMDAS) that you have to solve what is in parentheses first.
However, when there is ONLY addition in the problem it doesn't matter where the parenthesis is located because the answer will be the same.
1 + (2 + 7) = 10
(1 + 2) + 7 = 10
(The Parentheses can "associate" with different numbers)
REMEMBER: This cannot be used with subtraction!
When you add 0 to any number it keeps the same identity.
6 + 0 = 6
0 + 6 = 6
If you add the opposite of a number to itself then you will get 0.
6
The opposite of 6 is -6
-6 + 6 = 0
6 + -6 = 0