To reduce a fraction to the lowest terms equivalent: divide the numerator and denominator by their greatest common factor, GCF
To calculate the greatest common factor, GCF:
- 1. Factor the numerator and the denominator (into prime factors), build their prime factorizations.
- 2. Multiply all their common prime factors, taken by the lowest exponents.
1. Factor the numerator and the denominator:
To factor a number (into prime factors) - or, in other words, to break it down to prime factors - or, in other words, to build its prime factorization: find the prime numbers that multiply together to get that number.
The prime factorizations:
Written with exponents:
123,768 = 2 × 2 × 2 × 3 × 3 × 3 × 3 × 191 = 23 × 34 × 191
123,768 is a composite number.
Written with exponents:
1,528 = 2 × 2 × 2 × 191 = 23 × 191
1,528 is a composite number.
123,768/1,528 =
(123,768 ÷ 1,528) / (1,528 ÷ 1,528) =
81/1 =
81
* When it's 1, the denominator of the fraction can be omitted.
Yet another method to reduce the fraction
To reduce a fraction without calculating the GCF: factor its numerator and denominator, then all the common prime factors are easily identified and crossed out.
123,768/1,528 =
(23 × 34 × 191)/(23 × 191) =
((23 × 34 × 191) ÷ (23 × 191)) / ((23 × 191) ÷ (23 × 191)) =
34/1 =
34 =
81
* When it's 1, the denominator of the fraction can be omitted.