Fraction calculator
Exact fraction arithmetic with the working shown, from common denominator to simplest form.
Simplified fraction
Simplified fraction: 9/4
- Mixed number
- 2 1/4
- Decimal
- 2.25
Step by step
- 3/2 + 3/4
- = 6/4 + 3/4
- = 9/4
How it works
To add or subtract, the calculator rewrites both fractions over their lowest common denominator, then adds or subtracts the numerators.
To multiply, it multiplies the numerators and the denominators. To divide, it multiplies by the reciprocal of the second fraction.
The answer is reduced by the greatest common divisor of its numerator and denominator. All arithmetic is exact, with no rounding.
Formula
a/b + c/d = (ad + cb) / bd a/b − c/d = (ad − cb) / bd a/b × c/d = ac / bd a/b ÷ c/d = ad / bc
Worked example
1 1/2 + 3/4: write 1 1/2 as 3/2, then 3/2 + 3/4 = 6/4 + 3/4 = 9/4. As a mixed number that is 2 1/4, or 2.25 as a decimal.
Questions people ask
How do I enter a mixed number?
Type the whole number, a space, then the fraction: 2 1/3. For a negative mixed number put the minus sign first: −2 1/3.
How is a fraction simplified?
Divide the numerator and denominator by their greatest common divisor. 18/24 has a GCD of 6, so it simplifies to 3/4.
Can I mix fractions and decimals?
Yes. A decimal such as 0.25 is read exactly as 1/4, so the answer is still exact.