Why do you flip the second fraction when dividing?
Dividing by a quantity is mathematically identical to multiplying by its multiplicative inverse (reciprocal). Inverting the second fraction turns the division into standard multiplication.
Can the second fraction have a numerator of zero?
No. If the divisor numerator is zero, inverting it would put zero in the denominator, which is undefined division by zero.
Does the order matter when dividing fractions?
Yes. Division is non-commutative: (a/b) ÷ (c/d) produces a different result than (c/d) ÷ (a/b). The two results are reciprocals of each other.
What is the "Keep, Change, Flip" rule?
It is a common mnemonic for fraction division: Keep the first fraction the same, Change division to multiplication, and Flip the second fraction upside down.
How do you divide mixed fractions?
Convert each mixed number to an improper fraction first, then apply the Keep, Change, Flip rule.
How accurate is the result?
Results use JavaScript's 64-bit floating point — accurate to 15+ significant digits for most calculations.
Can I enter decimal numbers?
Yes, decimals are fully supported.
Is it free?
Yes, completely free.
Does it show the formula?
Yes, the formula is displayed on the page.
Can I use it on mobile?
Yes, the calculator is fully responsive.
Does it save my inputs?
No data is stored — all calculations are done locally in your browser.
What if I get an error?
Check for invalid inputs such as division by zero or negative square roots.