Fractions — add, subtract, multiply and divide with every step explained
Calculation
GCD and LCM of two numbers
GCD is the greatest common divisor: the largest number both numbers are divisible by. LCM is the least common multiple: the smallest number divisible by both. Example: GCD(12, 18) = 6, LCM(12, 18) = 36.
📚 Theory: how to work with fractions
Addition and subtraction: bring the fractions to a common denominator — best the LCM (least common multiple) of the denominators. Scale each fraction so the denominators match, then add the numerators.
Multiplication: numerator by numerator, denominator by denominator. Division is multiplication by the reciprocal fraction.
Reduction: divide numerator and denominator by their GCD (greatest common divisor). The GCD is found by Euclid's algorithm: replace the larger number by the remainder of division by the smaller one until the remainder is zero.
GCD and LCM are related: LCM(a, b) = a · b / GCD(a, b).
You can enter fractions (3/4), integers (5) and decimals (0.5 becomes 1/2).