Fraction Calculator
Fraction homework fails on the same step every time: 3/4 + 5/6 needs a common denominator before anything else can happen. This calculator works with whole-number numerators and denominators in both fractions, then returns the exact simplified answer — 19/12 — alongside the mixed number (1 7/12), the decimal, and the worked line that shows the common denominator it used, so the answer teaches the method instead of replacing it.
Division gets the same treatment with its own trick — flip and multiply — and every result is reduced by the greatest common divisor, with the divisor named in the note. Negative numerators work for subtracting-below-zero cases. Inputs are remembered on this device, which makes checking a whole worksheet's worth of problems a matter of editing two numbers between questions. It pairs with the roman numeral and prime factorization tools in the study corner of the site.
How to use
- Enter the numerator and denominator of each fraction as whole numbers.
- Choose add, subtract, multiply or divide — the answer updates live.
- Read the simplified fraction, mixed number and decimal; the note shows the steps.
Frequently asked questions
How do you add fractions with different denominators?
Rewrite both over the least common denominator, then add the numerators: 3/4 + 5/6 becomes 9/12 + 10/12 = 19/12. The calculator shows exactly this line, including the common denominator it chose, then simplifies the result by the GCD.
How do you divide fractions?
Multiply by the reciprocal: 3/4 ÷ 5/6 = 3/4 × 6/5 = 18/20 = 9/10. No common denominator needed — flip the second fraction and multiply. The note line writes out the flip so the habit sticks.
How do I simplify a fraction?
Divide numerator and denominator by their greatest common divisor. 18/20 share a GCD of 2, giving 9/10; the note names the divisor it used so you can check the work by hand. A fraction is fully simplified when nothing above 1 divides both parts.
Can this handle mixed numbers like 1 3/4?
Enter them as improper fractions — 1 3/4 is 7/4 — and the calculator returns the answer both ways: simplified improper and mixed. To convert by hand, multiply the whole by the denominator and add the numerator (1×4+3=7) over the original denominator.