The idea, step by step
Compare the same-sized parts
When denominators match, the pieces have equal size and the greater numerator gives the greater fraction. With different denominators, first rename the fractions with a common denominator.
For 3/4 and 5/6, twelfths are convenient. Renaming makes the parts directly comparable without changing either amount.
| Fraction | Equivalent twelfths |
|---|---|
| 3/4 | 9/12 |
| 5/6 | 10/12 |
Use benchmarks to check
A fraction below one half has a numerator less than half its denominator. A fraction above one half has a numerator greater than half its denominator. Benchmarks sometimes settle a comparison without a full common-denominator calculation.
For practical quantities, check that the wholes are equal. Fractions of differently sized bottles cannot tell you which contains more water unless you also know the bottle sizes.
A common trap
The fraction with the larger denominator is always greater.
Instead: More equal parts means smaller pieces. One eighth is smaller than one quarter of the same whole.
See the thinking
Worked example 1
Which is greater: or ?
- Rename them as 9/12 and 10/12.
- Ten twelfths are more than nine twelfths.
Worked example 2
Order , and from least to greatest.
- Use twenty-fourths: 16/24, 6/24 and 9/24.
- Order the numerators 6, 9, 16.
Check your understanding
Which is greater: or ?
Show answer
.
One half is 6/12, so 7/12 is greater.
Your turn
6 questions · 10 marks · Work at your own pace.
Read the questions online
- Compare and using < or >.1 mark
- Which is greater: or ?2 marks
- Order , and from least to greatest.2 marks
- Is below or above one half?1 mark
- Give a fraction strictly between and .2 marks
- Identical bottles are filled to and . Which contains more water?2 marks
Read the worked solutions
Equivalent correct methods earn the corresponding marks. Include units where asked.
- Compare and using < or >.1 mark
The pieces have the same size, so compare the numerators.
. - Which is greater: or ?2 marks
2/3=10/15 and 3/5=9/15.
. - Order , and from least to greatest.2 marks
Use twelfths: 6/12, 9/12 and 8/12.
. - Is below or above one half?1 mark
Half of 9 is 4.5; 4 is less than 4.5.
Below. - Give a fraction strictly between and .2 marks
1/2=2/4 lies between them. Other correct answers are possible.
For example, 1/2. - Identical bottles are filled to and . Which contains more water?2 marks
5/6=20/24 and 7/8=21/24.
The bottle filled to 7/8.
Curriculum reference & lesson scope
Australian Curriculum v9 and SA Curriculum Mathematics
Equivalence; comparing/ordering; addition/subtraction; practical quantities.
Official curriculum source ↗