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:
68 = 2 × 2 × 17 = 22 × 17
68 is a composite number.
500,000,090 = 2 × 5 × 17 × 1,451 × 2,027
500,000,090 is a composite number.
68/500,000,090 =
(68 ÷ 34) / (500,000,090 ÷ 34) =
2/14,705,885
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.
68/500,000,090 =
(22 × 17)/(2 × 5 × 17 × 1,451 × 2,027) =
((22 × 17) ÷ (2 × 17)) / ((2 × 5 × 17 × 1,451 × 2,027) ÷ (2 × 17)) =
2/(5 × 1,451 × 2,027) =
2/14,705,885
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
2/14,705,885 =
2 ÷ 14,705,885 =
0.000000136 ≈
0