The Fraction Calculator performs addition, subtraction, multiplication, and division on fractions. Results are reduced by dividing numerator and denominator by their greatest common divisor.
For addition and subtraction, convert to a common denominator first. Division by zero is invalid. Mixed-number interpretation depends on the input format.
Method
For addition and subtraction, a common denominator is selected and numerators are combined. Multiplication multiplies numerators and denominators. Division multiplies by the reciprocal of the second fraction, so a zero divisor is invalid. The result is reduced using the greatest common divisor.
Example
2/3 + 1/4 becomes 8/12 + 3/12 = 11/12. For 5/6 divided by 2/3, multiply by 3/2 to get 15/12, then reduce to 5/4.
Interpretation
Reduced and unreduced fractions have the same value, but reduced output is easier to compare and reuse. A negative sign on either one term has the same value as a negative numerator.
Common questions
What does a whole number mean?
It is equivalent to that number over 1 when whole-number input is supported.
Why reject division by zero?
A finite value is not defined for a fraction divided by zero.