Guide
How to Add, Subtract, Multiply and Divide Fractions
Learn the rules for fraction arithmetic, how to simplify results, and how to convert between fractions, mixed numbers and decimals.
A fraction calculator performs arithmetic on two fractions and returns the simplified result as a fraction, a mixed number, and a decimal. Understanding the rules behind the results helps you spot errors.
The four operations
- Add/subtract: find a common denominator, then add or subtract the numerators. 1/4 + 1/6 = 3/12 + 2/12 = 5/12.
- Multiply: multiply the numerators, then the denominators. 2/3 × 4/5 = 8/15.
- Divide: multiply by the reciprocal of the second fraction. 2/3 ÷ 4/5 = 2/3 × 5/4 = 10/12 = 5/6.
Simplifying and converting
Always simplify the result by dividing the numerator and denominator by their GCD. An improper fraction (numerator larger than denominator, e.g. 7/4) converts to a mixed number (1 3/4). Every fraction has a decimal equivalent (3/4 = 0.75).
How to use the calculator
- Enter the two fractions as numerator and denominator.
- Choose the operation.
- Read the simplified fraction, mixed number, and decimal.
Examples
1/2 + 1/3 = 5/6 (decimal 0.833…). 3/4 × 2/3 = 6/12 = 1/2 (decimal 0.5). 5/6 ÷ 1/2 = 5/3 = 1 2/3 (decimal 1.666…). The calculator shows all three forms so you can pick the one your context needs.
When a fraction calculator is useful
- Checking homework or tutoring maths.
- Adjusting recipe quantities expressed as fractions.
- Working with measurements in woodworking or sewing.
- Converting between fractional and decimal values.
Put it into practice
Use the Fraction Calculator right now — free, in your browser, no sign-up required.
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