Negative Integers
Understanding numbers less than zero
1. Why Do We Need Negative Numbers?
Natural numbers (1, 2, 3, 4, ...) and zero are great for counting objects, but they can't describe every situation in real life!
Temperature
What if it's colder than 0°C? We need numbers like −15°C
Depth
Below sea level? A submarine at −200 meters
Debt
Owe money? That's −500 som in your account
Floors
Basement levels: −1, −2, −3
Key Insight: We need numbers less than zero to describe situations that are "below," "before," "less than," or "opposite to" a reference point.
2. What Are Negative Numbers?
Definition
Negative numbers are numbers that are less than zero.
They are written with a minus sign (−) in front:
−1, −2, −3, −5, −10, −100
How to Read Them:
- −5 is read as "minus five" or "negative five"
- −12 is read as "minus twelve" or "negative twelve"
- −100 is read as "minus one hundred"