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:
81 = 3 × 3 × 3 × 3 = 34
81 is a composite number.
Written with exponents:
500,000,067 = 3 × 3 × 3 × 7 × 7 × 19 × 19,891 = 33 × 72 × 19 × 19,891
500,000,067 is a composite number.
81/500,000,067 =
(81 ÷ 27) / (500,000,067 ÷ 27) =
3/18,518,521
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.
81/500,000,067 =
34/(33 × 72 × 19 × 19,891) =
(34 ÷ 33) / ((33 × 72 × 19 × 19,891) ÷ 33) =
3/(72 × 19 × 19,891) =
3/18,518,521
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
3/18,518,521 =
3 ÷ 18,518,521 =
0.000000162 ≈
0