Mrs. Hill's Perfect P.I.R.A.T.E.S.: Properties of Addition

The properties of addition are the rules that make adding numbers easier. In third grade, we focus on three properties: the Commutative, Associative, and Identity Properties.

The Commutative Property is also known by younger students as "The Switch-a-roo". It tells us that it doesn't matter what order you add two numbers in the answer will still be the same. 3+4 is the same as 4+3 or 3+4=4+3.

The Associative Property is about grouping numbers that we are adding. When you add 3 or more numbers at a time, you naturally group two together first and then add in the next number. The Associative Property is shown by using parenthesis to show which numbers we are grouping together first to make adding easier. (3+4)+6 means that we are adding 3 and 4 together first then we add 7+6 to get 13. We can also add those numbers by adding 4+6 first to get 10 and then add 10+3 to get the sum of 13. It is shown as (3+4)+6=3+(4+6).

The Identity Property is about helping a number keep it's identity. Remember: identity is who or what something is. When adding two numbers together, the only way one of the numbers can stay what it is, is to add 0 to it. 5+0=5, because when you add nothing to a number the number does not change.

Here are the notes students should have in their notebook.