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Fraction Calculator
About the Fraction Calculator
Add, subtract, multiply and divide fractions and get the answer in simplest form. It is useful for homework, cooking measurements and DIY projects.
How to use the Fraction Calculator
- Enter the numerator and denominator of the first and second fractions.
- Choose an operation: +, −, × or ÷.
- Press Calculate Result to see the simplified fraction.
Formula and method
Add: a/b + c/d = (ad + bc) ÷ bd
Multiply: a/b × c/d = ac ÷ bd
Divide: a/b ÷ c/d = ad ÷ bc
The result is simplified by dividing the numerator and denominator by their greatest common factor.
Worked example
3/4 + 5/6: the common denominator is 12, so 9/12 + 10/12 = 19/12, which is 1 7/12 as a mixed number.
Adding unlike fractions. To add 1/2 and 1/3, find a common denominator of 6: 3/6 + 2/6 = 5/6.
When to use the Fraction Calculator
- Adding, subtracting, multiplying and dividing fractions for homework or cooking.
- Simplifying a fraction to its lowest terms.
- Checking your own working on fraction problems.
Common mistakes to avoid
- Adding the numerators and the denominators directly. 1/2 + 1/3 is not 2/5.
- Forgetting to flip the second fraction when dividing.
- Not simplifying the final answer.
Tips
- The denominator can never be zero.
- To divide by a fraction, multiply by its reciprocal.
- Always simplify your final answer.
Frequently Asked Questions
Convert both to a common denominator, add the numerators and keep the denominator.
Divide the numerator and the denominator by their greatest common factor. For 12/18 the factor is 6, so it simplifies to 2/3.
Multiply the first fraction by the reciprocal of the second. 1/2 ÷ 1/4 = 1/2 × 4/1 = 2.