A fraction with fractions inside it looks like a typo — but complex fractions show up every time you halve a recipe that calls for 2/3 cup. A complex fraction is a fraction whose numerator, denominator, or both contain fractions — like (2/3)/(4/5). The fix is beautifully mechanical: dividing by a fraction is multiplying by its reciprocal, so (2/3)/(4/5) becomes (2/3) × (5/4) = 10/12 = 5/6.

In the general form (a/b)/(c/d), the simplified result is (a×d)/(b×c): cross-multiply the outer terms for the new numerator and the inner terms for the new denominator, then reduce. Middle-schoolers meet them in pre-algebra, bakers meet them scaling recipes, and they lurk inside rational-expression problems in Algebra 2. A classic trap is adding the little fractions' numerators straight across — the reciprocal method exists precisely so you never do that. Enter the four parts and the calculator cross-multiplies, reduces via the GCD, and shows the decimal value for confirmation.

With the pre-filled defaults — Top numerator (a) 2, Top denominator (b) 3, Bottom numerator (c) 4, Bottom denominator (d) 5 — the Complex Fractions Calculator returns Result Numerator (a×d) 10, Result Denominator (b×c) 12, Decimal Value 0.83333333, GCD of result 2. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.