Like fractions and unlike fractions
Consider the following figures:
The fraction represented by (i) is 2/6. The fraction represented by
(ii) is 3/6. The fraction represented by (iii) is 4/6
In 2/6, 3/6 and 4/6 , the denominators are the same. Such fractions are called as like fractions.
Fractions with same denominators are called like fractions.
Examples 1/5, 4/5, 3/5
Fractions with different denominators are called unlike fractions.
Examples: 1/7, 2/9, 9/11
Converting unlike fractions into like fractions
To convert unlike fractions into like fractions, we change the denominators of the given fractions into a common denominator. This can be done by finding the common multiples of the denominator.
Convert 5/6 and 7/9 into like fractions.
Find common multiples for the numbers 6 and 9
Multiples of 6 : 6,12,18,24,30,36,…
Multiples of 9 : 9,18,27,36,45,…..
Here, the number 18 is a multiple of both 6 and 9 and so 18 is the first common denominator of both the fractions.
Thus 15/18 and 14/18 are like fractions,
repectively equivalent to 5/6 and 7/9
Covert 4/8 and 5/16 into like fractions.
As 16 is twice 8 it is easy to make 16 as the common denominator
Thus 8/16 and 15/16 are the required like fractions.
Find a common denominator for 2/5 and 3/7
The number 35 is a common multiple of both 7 and 5.
So, take 35 as the common denominator.
Therefore 14/35 and 15/35 are the required like fractions.