Integers
5 minQuiz at the end
What are Integers?
Integers are whole numbers that can be positive, negative, or zero: β¦-3, -2, -1, 0, 1, 2, 3β¦
They do not include fractions or decimals.
The Number Line
β -5 -4 -3 -2 -1 0 1 2 3 4 5 β
Numbers to the left are smaller. Numbers to the right are larger.
- -5 < -1 < 0 < 3 < 7
Adding Integers
- Positive + Positive: 4 + 3 = 7
- Negative + Negative: -3 + (-5) = -8 (add sizes, keep negative)
- Positive + Negative: 7 + (-4) = 3 (find the difference, use sign of larger)
Subtracting Integers
Subtracting a negative = adding: a - (-b) = a + b
- 5 - (-3) = 5 + 3 = 8
Multiplying and Dividing Integers
| Signs | Result |
|---|---|
| Positive Γ Positive | Positive |
| Negative Γ Negative | Positive |
| Positive Γ Negative | Negative |
| Negative Γ· Positive | Negative |
Key rule: Same signs β positive. Different signs β negative.
Real-World Context
Negative numbers represent: temperatures below zero, depths below sea level, debts, and going back in time.