Add, subtract, multiply, or divide fractions and mixed numbers. Shows step-by-step work and automatically simplifies results.
To add or subtract fractions, you need a common denominator. This is a shared bottom number that both fractions can be converted to. The easiest common denominator to use is the least common multiple (LCM) of the two denominators.
For example, to add 1/3 + 1/4, the LCM of 3 and 4 is 12. Convert: 1/3 = 4/12 and 1/4 = 3/12. Now add the numerators: 4/12 + 3/12 = 7/12. Subtraction works identically except you subtract the numerators.
Multiplying fractions is straightforward: multiply the numerators together and multiply the denominators together. For example, 2/3 x 3/4 = (2 x 3) / (3 x 4) = 6/12. Then simplify: 6/12 = 1/2. You can also cross-cancel before multiplying to keep the numbers smaller.
To divide fractions, multiply the first fraction by the reciprocal of the second. The reciprocal is the fraction flipped upside down. For example, 2/3 / 4/5 = 2/3 x 5/4 = 10/12 = 5/6.
A fraction is in simplest form when the numerator and denominator share no common factors other than 1. To simplify, divide both by their greatest common divisor (GCD). For 6/12, the GCD is 6, so 6/12 = 1/2. This calculator automatically simplifies all results.
A mixed number combines a whole number with a fraction, like 2 1/3. To use mixed numbers in calculations, first convert to an improper fraction: multiply the whole number by the denominator, add the numerator, and keep the same denominator. So 2 1/3 = (2 x 3 + 1)/3 = 7/3.