How to use this calculator
Enter whole-number numerators and nonzero denominators, then choose addition, subtraction, multiplication or division. The result includes a simplified fraction and a decimal approximation.
How fractions are combined
Addition and subtraction use a common denominator. Multiplication multiplies the numerators and denominators; division multiplies by the reciprocal of the second fraction. The greatest common divisor reduces the answer, and a negative denominator is moved into the numerator.
Input limits and decimal approximations
A denominator cannot be zero, and division by a zero fraction is undefined. Inputs and intermediate integer arithmetic must stay within the supported safe-integer range. A repeating decimal is an approximation; keep the simplified fraction when an exact answer matters.
Example: adding different denominators
For 1/2 + 1/3, the common denominator is 6. Adding 3/6 and 2/6 gives 5/6, approximately 0.833333.