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:
18,508 = 2 × 2 × 7 × 661 = 22 × 7 × 661
18,508 is a composite number.
Written with exponents:
399,960 = 2 × 2 × 2 × 3 × 3 × 5 × 11 × 101 = 23 × 32 × 5 × 11 × 101
399,960 is a composite number.
18,508/399,960 =
(18,508 ÷ 4) / (399,960 ÷ 4) =
4,627/99,990
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.
18,508/399,960 =
(22 × 7 × 661)/(23 × 32 × 5 × 11 × 101) =
((22 × 7 × 661) ÷ 22) / ((23 × 32 × 5 × 11 × 101) ÷ 22) =
(7 × 661)/(2 × 32 × 5 × 11 × 101) =
4,627/99,990
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
4,627/99,990 =
4,627 ÷ 99,990 =
0.046274627463 ≈
0.05