To compare 2/3 and 3/5, make the denominators the same. Use a common denominator, a number both denominators go into. Here 15 works: 2/3 = 10/15 and 3/5 = 9/15. Now compare the numerators: 10/15 > 9/15, so 2/3 > 3/5.
You can also compare each fraction with 1/2. 3/8 is less than a half and 5/9 is more than a half, so 5/9 is bigger, with no working needed.
Worked example
Which is greater: 3/4 or 5/6?
- Use 12 as a common denominator: 3/4 = 9/12 and 5/6 = 10/12.
- 10/12 is more than 9/12.
Answer:5/6
Key words
- common denominator
- a shared bottom number
- benchmark
- a known fraction such as 1/2 used to compare
- numerator
- the top number
Practise this
New questions every time.
Common Core-referenced: 4.NF.A.2