What is Unlike Denominators? - Definition, Facts & Example

What is Unlike Denominators?

Two fractions with non-identical denominators are known as unlike denominators.

It is challenging to compare fractions having unlike denominators. Also, performing the operations of addition and subtraction of fractions with unlike denominators is difficult. Hence, to compare and order, or to add and subtract fractions with unlike denominators, we first convert these fractions to like fractions, that is, fractions with same denominators.

For example, to compare the fractions ³⁄₄ and ⁵⁄₇, we first draw the fraction models and then compare the two fractions.

$compare fractions having unlike denominators$

Looking at the shaded parts of the figures, we can say that ³⁄₄ is greater than ⁵⁄₇. However, drawing fraction models is not convenient at all times. In such cases, we need to find a way out to compare fractions with unlike denominators.

Converting unlike denominators to like denominators or common denominator:

To convert the fractions with unlike denominators to like denominators or common denominator, we follow the given steps.

Step 1: Find the least common multiple (LCM) of the denominators.

Multiples of 4: 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, ...

Multiples of 7: 7, 14, 21, 28, 35, 42, 49, 56, 63, 70,...

LCM of 4 and 7 is 28

Step 2: Multiply both the numerator and the denominator of each fraction by a number to get the obtained LCM as the denominator.