Fraction Calculator

Add, subtract, multiply, or divide fractions for homework, recipes, measurements, and other jobs involving awkward little numbers.

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Enter the numerator and denominator of each fraction, choose an operation, and calculate. Denominators cannot be zero, and division also requires the second numerator to be nonzero.

For a/b + c/d, use (a × d + b × c)/(b × d). For subtraction, use (a × d - b × c)/(b × d). For multiplication, use (a × c)/(b × d). For division, use (a × d)/(b × c), then reduce the result by dividing both parts by their greatest common divisor.

Worked example

To add 3/4 and 2/5, calculate (3 × 5 + 4 × 2)/(4 × 5) = 23/20. The result is 23/20, or 1 3/20 as a mixed number.

Common questions

Why does the answer get simplified?

Equivalent fractions represent the same value, so 6/8 can be reduced to 3/4. Simplifying makes the result easier to read and compare.

Can a fraction have zero on the bottom?

No. Division by zero is undefined, so a denominator of zero does not represent a valid number.

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