Multiplying fractions. How to multiply ordinary math fractions? Steps. Example.
How to multiply two fractions?
When we multiply ordinary fractions, the end fraction will have:
- as a numerator, the result of multiplying all the numerators of the fractions,
- as a denominator, the result of multiplying all the denominators of the fractions.
- a/b × c/d = (a × c) / (b × d)
- a, b, c, d are integer numbers;
- if the pairs (a × c) and (b × d) are not coprime (they have common prime factors) the end fraction should be reduced (simplified) to lower terms.
How to multiply ordinary fractions? Steps.
- Start by reducing fractions to lower terms (simplifying).
- Internal link > Reduce common ordinary fractions to the lowest terms, online, with explanations
- Factor the numerators and the denominators of the reduced fractions: break them down to their prime factors.
- External link > Check whether numbers are prime or not. Calculate the prime factors of the composite numbers, online calculator.
- Above the fraction bar we write the product of all the prime factors of the fractions' numerators, without doing any calculations.
- Below the fraction bar we write the product of all the prime factors of the fractions' denominators, without doing any calculations.
- Cross out all the common prime factors that appear both above and below the fraction bar.
- Multiply the remaining prime factors above the fraction bar - this will be the numerator of the resulted fraction.
- Multiply the remaining prime factors below the fraction bar - this will be the denominator of the resulted fraction.
- There is no need to reduce (simplify) the resulting fraction, since we have already crossed out all the common prime factors.
- If the resulted fraction is an improper one (without considering the sign, the numerator is larger than the denominator), it could be written as a mixed number, consisting of an integer and a proper fraction of the same sign.
- Internal link > Reduce (simplify) and write improper fractions as mixed numbers, online calculator
- Internal link > Multiply common ordinary fractions, online, with explanations