Lesson 18: Subtracting Fractions (Different Denominators)
To subtract fractions with different denominators, you must find a common denominator so the fractions can be compared and subtracted correctly.
Steps to Subtract Fractions with Different Denominators
- Find the Least Common Denominator (LCD).
- Rewrite each fraction with the LCD.
- Subtract the numerators.
- Keep the common denominator.
- Simplify the result if possible.
Example
2/3 - 1/6 ? LCD is 6 ? 4/6 - 1/6 = 3/6 ? Simplify ? 1/2
3/4 - 1/2 ? LCD is 4 ? 3/4 - 2/4 = 1/4
Helpful Tips
Always simplify your answer and check for accuracy.
Only subtract when the first numerator is larger after rewriting.
Need a little helping hand?