Addition of Integers
Learn how to add positive and negative numbers like a pro!
1. Adding on the Number Line
The Big Idea
- Adding a positive number: Move RIGHT →
- Adding a negative number: Move ← LEFT
Example: 3 + (−5)
- Start at 3 on the number line
- Adding −5 means move 5 steps LEFT
- Land on −2
Answer: 3 + (−5) = −2
Interactive visualization — available in the full lesson
2. Adding Two Positive Integers
This is just like adding natural numbers — nothing new!
Rule: Add the numbers normally. Result is always POSITIVE
Examples:
- 5 + 3 = 8
- 12 + 7 = 19
- (+4) + (+6) = +10
3. Adding Two Negative Integers
Think of it as combining two debts — you owe even more!
Rule: Add the absolute values, then put a MINUS SIGN
Examples:
- (−3) + (−5) = −8
- (−10) + (−4) = −14
- (−4) + (−6) = −10