Understand that positive and negative numbers describe quantities having opposite directions or values

What you'll learn

1. Recognize that positive and negative numbers describe quantities measured in *opposite directions* from a chosen zero.
2. Identify what zero represents in a real-world context: freezing for Celsius temperature, sea level for elevation, balanced for an account, neutral for electric charge.
3. Use positive and negative numbers to represent real-world quantities (write "-200 ft" for "200 feet below sea level"; write "+8,848 m" for "Mount Everest's elevation"; write "-$30" for "owing $30").
4. Interpret a signed value back into context language ("-12 degreesC" -> "12 degrees below freezing"; "-$30 balance" -> "owes $30").
5. Recognize the *opposite* relationship between numbers like +3 and -3, and connect it to real-world opposites (deposit/withdrawal, climb/descend, gain/loss).