Addition

Background 

Now that we have Counting/Natural Numbers and the Number Line, can we start to use them?

Question 

How do I add? What are some words associated with addition?

Answer 

See below for how to add and also for terminology

Analysis 

Let's start with the Number Line to see how we add:



Let's put a blue dot on the number 1:



That dot means we have 1 of something. Perhaps we have one paperclip or one book or one channel we watch on Youtube. It's one of something.

What happens when we get another of that same thing? We now have 2 of them. To express this as addition, what we do is start with 1, add 1 (and we can use the + sign to indicate that), and then say that it equals 2 (and we show equals with the = sign). Ok - let's write this out step by step:

1 plus 1 equals 2

1 + 1 = 2

On the Number Line, we can graph this. We start at the blue 1. Since we are adding 1 (+ 1) to the blue 1, we move one spot to the right of the blue 1 and end up at the orange 2. I'll show the movement from the blue 1 to the orange 2 with a line connecting the two:



See how the first number tells us where to start? And how the amount that we add by tells us the number of numbers to move to the right?

Let's try another. Let's start with 3 and add 2 more. We put a dot (it can be any colour) on the number 3 and then we move up (to the right) by 2 more spots:



So that's 3 + 2 = 5

Let's talk about addition terminology:

The numbers that we are adding together (so both the starting point and the number(s) we're adding) are called terms. (They can also be called addends). The number that we get to as a result of adding (like the 5 above) is called the total or sum).

In word problems, look for words like sum, total, add, increase, and plus to indicate that addition is needed.

For more information check out these links (comment to add a resource to the list!): 

Where might you have come from? 

Fact-orials Index

Numbers:

• The Number 1
• Counting/Natural Numbers

Where might we go?

Numbers:

• The Number 0

Operations:

• Subtraction
• Multiplication
• Grouping Terms, Parentheses
• Order of Operations

Operations with different kinds of numbers:

• Addition, Subtraction, and Whole Numbers
• Addition, Subtraction, and Variables

Properties:

• Commutative Property
• Associative Property

Relations:

• Equality
• Inverse Relations