Fraction Arithmetic Formulas
Addition and subtraction require a common denominator, found using the Least Common Multiple (LCM) of the two denominators, before combining numerators: (a/b) ± (c/d) becomes equivalent fractions over the LCD. Multiplication multiplies numerators and denominators directly: (a/b) × (c/d) = (a×c)/(b×d), while division multiplies by the reciprocal of the second fraction: (a/b) ÷ (c/d) = (a/b) × (d/c).