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:
18,512 = 2 × 2 × 2 × 2 × 13 × 89 = 24 × 13 × 89
18,512 is a composite number.
399,966 = 2 × 3 × 7 × 89 × 107
399,966 is a composite number.
18,512/399,966 =
(18,512 ÷ 178) / (399,966 ÷ 178) =
104/2,247
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.
18,512/399,966 =
(24 × 13 × 89)/(2 × 3 × 7 × 89 × 107) =
((24 × 13 × 89) ÷ (2 × 89)) / ((2 × 3 × 7 × 89 × 107) ÷ (2 × 89)) =
(23 × 13)/(3 × 7 × 107) =
104/2,247
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
104/2,247 =
104 ÷ 2,247 =
0.046283934134 ≈
0.05