Fractions on a Number Line
Learn to place fractions on a number line and understand their size and position.
For Elementary Students
Whole Numbers on a Number Line
You already know how to show whole numbers on a number line:
0 ─── 1 ─── 2 ─── 3 ─── 4 ─── 5
But what about numbers between 0 and 1? That's where fractions come in!
Fractions Fill the Gaps
Fractions are numbers that go between whole numbers.
Think about it like this: If whole numbers are the big marks on a ruler, fractions are all the little marks in between!
Halves on a Number Line (1/2)
To show halves, divide each space into 2 equal parts.
0 ───────── 1/2 ───────── 1
1/2 is exactly halfway between 0 and 1.
Fourths on a Number Line (1/4, 2/4, 3/4)
To show fourths (quarters), divide the space from 0 to 1 into 4 equal parts.
0 ─── 1/4 ─── 2/4 ─── 3/4 ─── 1
(1/2)
Notice: 2/4 is the same spot as 1/2! (They're equivalent fractions.)
Thirds on a Number Line (1/3, 2/3)
To show thirds, divide from 0 to 1 into 3 equal parts.
0 ──── 1/3 ──── 2/3 ──── 1
Each piece is one third of the way from 0 to 1.
Placing a Fraction
Example: Show 3/4 on a number line.
Step 1: Draw a line from 0 to 1
Step 2: Divide it into 4 equal parts (because the denominator is 4)
Step 3: Count 3 parts from 0 (because the numerator is 3)
start count 3
↓ → → →
0 ─── 1/4 ─── 2/4 ─── 3/4 ─── 1
↑
here!
Answer: 3/4 is at the third mark.
For Junior High Students
Fractions Beyond 1
Fractions can be greater than 1 — they go past the whole number 1!
Example: Show 5/4 on a number line.
0 ─── 1/4 ─── 2/4 ─── 3/4 ─── 1 ─── 5/4 ─── 6/4 ─── 7/4 ─── 2
(1/2) (4/4) (1¼) (1½) (1¾) (8/4)
5/4 is the same as 1¼ (one and one fourth).
Mixed Numbers on a Number Line
Mixed numbers like 1½ can be shown too.
Example: Place 2⅓ on a number line.
0 ─── 1 ─── 2 ─── 2⅓ ─── 2⅔ ─── 3
↑
here
2⅓ is just past 2, one-third of the way to 3.
Comparing Fractions Using a Number Line
A number line makes it easy to see which fraction is larger.
Example: Which is bigger: 2/5 or 3/5?
0 ─── 1/5 ─── 2/5 ─── 3/5 ─── 4/5 ─── 1
↓ ↓
smaller larger
3/5 is farther right, so 3/5 > 2/5.
Example: Which is bigger: 1/3 or 1/4?
0 ──── 1/4 ──── 1/3 ──── 1/2 ──── 1
↓ ↓
smaller larger
1/3 is farther right, so 1/3 > 1/4.
Why? When you cut something into fewer pieces (3 instead of 4), each piece is bigger!
Equivalent Fractions on a Number Line
Equivalent fractions land on the same point.
Example: 1/2, 2/4, and 3/6 are all equivalent.
Number line for halves:
0 ─────────── 1/2 ─────────── 1
Number line for fourths:
0 ─── 1/4 ─── 2/4 ─── 3/4 ─── 1
↑
same spot!
Number line for sixths:
0 ── 1/6 ── 2/6 ── 3/6 ── 4/6 ── 5/6 ── 1
↑
same spot!
All three fractions are at the same location: halfway between 0 and 1.
Distance on a Number Line
The distance from one fraction to another can be found by subtracting.
Example: What's the distance from 1/4 to 3/4?
0 ─── 1/4 ─── 2/4 ─── 3/4 ─── 1
↓ ↓
start end
←─────────→
2/4 = 1/2
Distance: 3/4 - 1/4 = 2/4 = 1/2
Benchmark Fractions
Some fractions are useful as benchmarks (reference points):
| Benchmark | Location |
|---|---|
| 0 | Start |
| 1/4 | Quarter of the way |
| 1/2 | Halfway |
| 3/4 | Three quarters |
| 1 | One whole |
You can estimate other fractions by comparing to these!
Example: "Is 5/8 closer to 1/2 or 1?"
0 ──── 1/4 ──── 1/2 ──── 5/8 ──── 3/4 ──── 1
↑
5/8 is between 1/2 and 3/4, closer to 1/2.
Fractions with Different Denominators
To show fractions with different denominators on one number line, find a common division.
Example: Show 1/2, 1/3, and 1/6 together.
Use sixths (since 6 is divisible by 2 and 3):
0 ── 1/6 ── 2/6 ── 3/6 ── 4/6 ── 5/6 ── 1
↑ ↑
1/3 1/2
- 1/6 = 1/6
- 1/3 = 2/6
- 1/2 = 3/6
Real-Life Number Lines
- Measuring cups (1/4 cup, 1/2 cup, 3/4 cup markings)
- Rulers (fractions of an inch: 1/2", 1/4", 1/8")
- Timelines (showing parts of an hour, day, year)
Practice
Where is 1/2 on a number line from 0 to 1?
Which fraction is larger: 2/3 or 1/3?
If you divide 0 to 1 into 4 equal parts, where is 3/4?
Where is 5/4 on a number line?