Fraction calculator (add, subtract, multiply, divide)
Enter two fractions, choose an operation, and this calculator shows the whole method: the common denominator for adding and subtracting, the flip-and-multiply step for division, then the simplified answer as a fraction, a mixed number and a decimal. Everything stays exact — no rounding errors creeping into your working.
Enter two fractions and choose an operation
2/3 + 3/4 = 17/12
Before simplifying: 17/12
As a mixed number: 1 5/12
Decimal: 1.416667
Working
- Common denominator = LCM of 3 and 4 = 12
- 2/3 = 8/12 and 3/4 = 9/12
- 8 + 9 = 17, over 12
The method behind it
- Add/subtract: common denominator first, then combine numerators only.
- Multiply: numerators × numerators, denominators × denominators.
- Divide: multiply by the reciprocal of the second fraction, then cancel.
How to use this tool
1. Type both fractions
Enter the numerator and denominator of each fraction. Negative numerators are fine; denominators cannot be zero.
2. Pick the operation
Choose add, subtract, multiply or divide. The steps update to match the method for that operation.
3. Simplify and convert
The answer is cancelled to its lowest terms and also shown as a mixed number, which is usually the form the mark scheme wants.
Frequently asked questions
How do you add fractions with different denominators?
Find a common denominator — the lowest common multiple of the two denominators works best — rewrite both fractions over it, then add the numerators only. Simplify the result at the end.
How do you divide fractions?
Keep the first fraction, flip the second (use its reciprocal) and multiply. So a/b ÷ c/d = a/b × d/c = ad/bc, then cancel down.
Do I have to simplify my answer?
Give the answer in its simplest form unless the question says otherwise. Many mark schemes award the final accuracy mark only for a fully cancelled fraction or a correct mixed number.
How do you turn an improper fraction into a mixed number?
Divide the numerator by the denominator. The whole-number part of the division is the integer, and the remainder over the original denominator is the fractional part — for example 17/5 = 3 2/5.
Practise this properly, not just once
A solver gives you the answer; exam marks come from the working. MathsGradeUp pairs exam-board questions with step-by-step feedback and revision notes on the exact topics you keep dropping marks on.