Example
For 1/2 + 1/4, convert 1/2 to 2/4, then add 2/4 + 1/4 = 3/4. For 2/3 x 3/5, multiply across to get 6/15 and reduce to 2/5.
How addition and subtraction work
Fractions need a common denominator before they can be added or subtracted. For 1/2 + 1/4, convert 1/2 to 2/4, then add 2/4 + 1/4 = 3/4.
How multiplication and division work
For multiplication, multiply numerators and denominators: 2/3 x 3/5 = 6/15 = 2/5 after reduction. For division, multiply by the reciprocal: 2/3 divided by 3/5 = 2/3 x 5/3 = 10/9.
Reduction
The calculator reduces the final fraction by dividing numerator and denominator by their greatest common divisor. A reduced fraction is mathematically equivalent but easier to read.
Common mistakes
- Adding denominators directly, such as treating 1/2 + 1/4 as 2/6.
- Using a zero denominator. A denominator cannot be zero.
- Dividing by a fraction with a zero numerator, which would mean division by zero.
- Forgetting to reduce the final result.
When this calculator is not enough
This tool handles two numeric fractions at a time. Use an algebra calculator for fractions containing variables or equations.
Last reviewed: 2026-05-17