Refresher · Signed numbers · about 12 min Pending teacher review
Where numbers live: the number line
Goal: Locate any integer on a number line, explain where zero sits, and describe a number's size as its distance from 0.
Before this: Needs counting and reading a scale (whole numbers). No signed-number work is assumed.
Step 1 · Launch (≈5 min)
Look at this number line. Zero is the middle marker, not the start. Numbers to the right of 0 are positive; numbers to the left are negative.
Find $-3$ and $3$. What do they have in common? What is different?
Say it out loud: "$-3$ is three units from zero, on the left."
Step 2 · Practice (≈10 min)
Pick the level that fits today. Hints are allowed — each one is recorded as assisted practice, which never changes an independent status.
Which number is marked by the point? (The line goes from $-5$ to $5$.)
What number is 4 units to the left of 0?
How far from 0 is $-6$?
Which number is marked by point $A$?
What number is the same distance from 0 as $9$, but on the other side?
Point $B$ is 2 units to the right of $-5$. What number is $B$?
Each tick on this line is 2 units. What number is point $C$?
A number is 5 units from 0 and is less than 0. What is it?
Two numbers are each 4 units from 0. What is their sum? (Hint: think about where they sit.)
Show me how it works — worked explanation
Reading a number line is two questions: **which side of zero?** and **how many units from zero?**
- Find 0. Everything to the left is negative; everything to the right is positive.
- Count units from 0 to the point. That count is the distance (always positive).
- Attach the sign for the side: left → put a minus sign in front.
- Example: a point 3 ticks left of 0 is $-3$; its distance from 0 is 3.
Step 3 · Wrap-up (≈5 min)
Every integer has two pieces of information: its side (the sign) and its distance from 0 (its size). $-3$ and $3$ have the same size and opposite sides. Zero is the balance point in the middle.
Step 4 · Independent check
4 fresh problems on this skill, done alone: no hints, no worked solutions, no feedback until the end. This is what moves the skill's status.
You can start the check any time, but the wrap-up is worth reading first.