Properties of Addition Today you will learn the three Properties of Addition: Associative Commutative Zero

Adding numbers together is easier if you find numbers that are “friendly”…numbers that end in 0 are very nice to work with! Let’s say you want to add three numbers. 42 + 7 + 10 It doesn’t matter what order you add them in, they will still add up to the same number. This is called the Associative Property. Think about the word, Associative…do you know the word, Associate?

But other times Tammy and Mary hang out. Associate means interacting with others. Let’s take three friends. Sometimes Mary and Nelly hang out. But other times Tammy and Mary hang out. Sometimes Nelly and Tammy hang out. Even though they don’t always hang out together, they are all friends. Each girl can hang out with the other one and still be friends with both.

Now let’s go back to our problem. 42 + 7 + 10 Because of the Associative Property, we can add the numbers up in any order. Remember numbers with 0 are friendly, so let’s start with 10 + 42. 10 + 42 = 52 Now add in the 7. 52 + 7 = 59 Adding friendly numbers together first is very helpful!

There’s another property you need to know! The Commutative Property means that if you are adding two numbers together, you can switch the order and you’ll get the same sum. In the word, Commutative, can you hear the word, commute? Commute means the distance between two places.

Think about my commute from my house to school each day. I get in my car and come to school. In the afternoon, I get in my car to go home. I travel the same distance in the same path. I travel the same distance whether I’m going from home to school, or from school to home.

It works the same way with the Commutative Property. If I am adding 12 + 10, I will get the same answer if I add 10 + 12. 12 + 10 = 22 10 + 12 = 22 So….12 + 10 is the same as 10 + 12. We can say 12 + 10 = 10 + 12 because both sums are 22.

One more property you need to know is the Zero Property. This property is EASY to understand! It says that no matter what number you add to 0, you will always get that other number. For example, if you add 4 to 0, you’ll get 4. 4 + 0 = 4. What if I add 99 to 0? 99 + 0 = ? You’re right 99!