ToolnozaSet up the calculation
Enter each numerator and denominator separately and select the operation. Keep a negative sign with the numerator to make the expression easier to read. A zero denominator does not define a valid fraction.
Addition and subtraction
Find a common denominator before combining numerators. For 1/6 + 1/4, the least common denominator is 12: 2/12 + 3/12 = 5/12. Subtraction uses the same method, with a minus between the adjusted numerators.
Multiplication
Multiply numerators together and denominators together. For 2/3 × 3/5, the result is 6/15, simplified to 2/5. Cancelling common factors before multiplying keeps intermediate numbers smaller.
Division
Multiply by the reciprocal of the second fraction. For 2/3 ÷ 4/5, calculate 2/3 × 5/4 = 10/12 = 5/6. Division by a zero-valued fraction is undefined, even if its denominator is valid.
Check the answer
Reduce numerator and denominator by their greatest common divisor. A decimal is a useful check but can be rounded: 1/3 is not exactly 0.3333. For a mixed number such as 1 1/2, first convert it to 3/2 before entering separate numerator and denominator fields.