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How to subtract fractions with common or uncommon denominators, like or unlike denominators?
Subtracting fractions can be done in a couple of ways, depending on whether the fractions have the same (common) denominator or different (uncommon) denominators
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.
Printable
Add/Subtract Fractions
Add Like Fractions
Add Unlike Fractions
Subtract Like Fractions
Subtract Unlike Fractions
Subtract Fraction from Whole Number
Online
Add (common denominator, no reducing)
Subtract (common denominator, no reducing)
Add/Subtract (common denominator, reducing)
Least Common Denominator
Add/Subtract (unlike denominators, guided)
Add/Subtract (unlike denominators)
When we subtract fractions that have the same, or common denominators, we subtract only the numerators. The denominators stay the same.
Example:
\(\frac{3}{7}-\frac{2}{7}=\frac{3-2}{7}=\frac{1}{7}\)
How to subtract fractions with common denominators.
To subtract fractions with uncommon denominators, we need to change the fractions to equivalent fractions with common denominators before we find the difference.
Example:
\(\frac{1}{2}-\frac{2}{5}\)
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.
\(\frac{1}{2}=\frac{1×5}{2×5}=\frac{5}{10}\)
\(\frac{2}{5}=\frac{2×2}{5×2}=\frac{4}{10}\)
Step 3: Subtract the 2 equivalent fractions.
\(\frac{1}{2}-\frac{2}{5}=\frac{5}{10}-\frac{4}{10}=\frac{1}{10}\)
How to subtract fractions with uncommon denominators?
Summary
Try out our new and fun Fraction Concoction Game.
Add and subtract fractions to make exciting fraction concoctions following a recipe. There are four levels of difficulty: Easy, medium, hard and insane. Practice the basics of fraction addition and subtraction or challenge yourself with the insane level.
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