Calculate with Fraction
Your result will appear here.
Formula and variables
- a, c
- the numerators
- b, d
- the nonzero denominators
For addition and subtraction, cross-multiply to form a common denominator. Multiplication combines numerators and denominators directly; division multiplies by the reciprocal.
Domain note: Numerators and denominators must be whole numbers. Denominators cannot be zero, and division by a zero fraction is not allowed.
How to use this calculator
- 1
Enter the numerator and denominator of each fraction.
- 2
Choose an operation.
- 3
Press Calculate fractions.
- 4
Review the reduced exact result, mixed number, and decimal approximation.
A complete example
Problem: Add 2/3 and 5/6.
Substitution: (2 × 6 + 5 × 3) / (3 × 6)
Result: 27/18 = 3/2 = 1 1/2
The exact sum is three halves, which is one and one-half.
Understand the result
The exact result is reduced using the greatest common divisor. The decimal is an approximation when the rational value does not terminate.
Common mistakes
- Adding denominators when adding fractions.
- Leaving a zero in the denominator.
- Dividing without multiplying by the reciprocal of the second fraction.
Frequently asked questions
Does the calculator reduce fractions?
Yes. It divides the numerator and denominator by their greatest common divisor.
Can I use negative fractions?
Yes. Enter a negative numerator or denominator; the normalized result places the sign in the numerator.
Why is the decimal sometimes rounded?
Some fractions have repeating decimal expansions. The exact reduced fraction remains the authoritative result.