Subtracting Fractions (common or uncommon denominators)
More Lessons for Arithmetic
Math Worksheets
The following diagram shows how to subtract fraction with common denominators and uncommon denominators. Scroll down the page for more examples and solutions for subtracting fractions.
Subtracting Fractions with Common Denominators or Like Denominators
When we subtract fractions that have the same, or common denominators, we subtract only the numerators. The denominators stay the same.
Example :
How to subtract fractions with common denominators.
Subtracting Fractions With Uncommon Denominators or Unlike Denominators
To subtract fractions with uncommon denominators, we need to change the fractions to equivalent fractions with common denominators before we find the difference.
First, we would need to find the least common denominator (LCD), which is the LCM of the denominators.
Next, we write equivalent fractions using the least common denominator. Then, we proceed to subtract as before.
Example:
Evaluate 
Solution:
Step 1 : Find the LCD or LCM of 2 and 5
Multiples of 2: 2, 4, 6, 8, 10, 12
Multiples of 5: 5, 10, 15
The LCD or the Least Common Multiple of 2 and 5 is 10
Step 2 : Write both fractions as equivalent fractions with a common denominator of 10.
Step 3: Subtract the 2 equivalent fractions.
How to subtract fractions with uncommon denominators?
Rotate to landscape screen format on a mobile phone or small tablet to use the Mathway widget, a free math problem solver that answers your questions with step-by-step explanations.
You can use the free Mathway calculator and problem solver below to practice Algebra or other math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.
We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.