What is a number line?
A number line is a straight line with numbers placed in order. Each number sits on a tick mark, and the marks are equally spaced.
0 — 1 — 2 — 3 — 4 — 5 — 6 — 7 — 8 — 9 — 10
Numbers get bigger as you move right and smaller as you move left.
Why number lines help
A number line turns numbers into places. That lets you see:
- Which number is bigger: the one further right.
- How far apart two numbers are: the distance between them.
- What happens when you add or subtract: you jump right or left.
Moving along the line
| Action | Direction | Example |
|---|---|---|
| Count on / add | Right | Start at 3, jump 2 right → 5 |
| Count back / subtract | Left | Start at 8, jump 3 left → 5 |
When you jump, count the jumps, not the tick marks. Your starting number is where you stand, not your first step.
Finding the distance
To find how far 3 is from 7, count the jumps from 3 to 7: 4, 5, 6, 7. That is 4 jumps, so the distance is 4.
Empty number lines
As you get older, you can draw an empty number line with no marks, just the numbers you need. To work out 28 + 5, draw 28, jump 2 to 30, then jump 3 to 33. Number lines grow with you: later they show negative numbers, fractions and decimals too.
Worked examples
Example 1: On a number line, which number is two steps right of 5?
Start at 5. Jump once to 6, twice to 7. Answer: 7.
Example 2: Start at 9 and jump 4 steps left. Where do you land?
8, 7, 6, 5. Answer: 5.
Example 3: Which is bigger, 6 or 4? Use a number line.
6 is further right, so 6 is bigger.
Common mistakes
- Counting the starting point as the first step. If you start at 5 and say "5, 6" for two steps, you land on 6 instead of 7. The first jump takes you to 6.
- Uneven spacing when drawing your own line. Keep the gaps the same.
- Moving the wrong direction for adding or taking away.
Try it yourself
- Start at 2 and jump 5 to the right.
- Start at 10 and jump 3 to the left.
- How many jumps from 4 to 9?
- Is 8 to the left or right of 3?
Answers: 1) 7 2) 7 3) 5 4) right
Quick recap
- A number line shows numbers in order with equal spaces.
- Right means bigger or adding; left means smaller or subtracting.
- Count the jumps to find the distance.