In this lesson:
The forecast: temperature drops from to overnight.
0°F is not "no temperature" — it is a specific real value
A debt is a real quantity — is not an error
A negative charge is not "bad" — it is a real property
In every context: 0 is the boundary between the two directions
Floors in a building:
In this building context: what does 0 represent?
Write your answer in one sentence before advancing.
Try each problem — then advance for answers:
Direction A (description → number):
Direction B (number → description): 4. in a temperature context 5. in an elevation context 6. in a bank account context
Pause here and write your six answers.
Direction A:
Direction B: 4. → 31 degrees below zero 5. m → 430 meters below sea level 6. → deposit (or credit)
Yes — context determines meaning, not the number alone.
What would mean in each of these three contexts?
What does 0 represent here? Sea level — average ocean surface height
Positive = money received; negative = money spent
Every signed number situation has the same structure:
Football, building floors, golf score — all fit this structure too
A drive: , , , ,
Pause and write your four answers.
✓ Positive and negative numbers describe opposite directions from a reference point ✓ The sign shows the direction; the magnitude shows the distance from 0 ✓ 0 is the reference — specific and meaningful in every context, never just "nothing" ✓ To assign a sign: identify the reference → find the direction → assign + or −
Watch out: Negative does not mean wrong — m is a precise location Watch out: is not "no temperature" — it is a specific real value Watch out: Underline the direction word first, then assign the sign Watch out: already means below zero — never write " degrees below zero"
Next: Locating Rational Numbers on the Number Line
Today's extended number line carries directly into 6.NS.C.6.