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:
4 = 2 × 2 = 22
4 is a composite number.
Written with exponents:
199,999,999,998 = 2 × 3 × 3 × 21,649 × 513,239 = 2 × 32 × 21,649 × 513,239
199,999,999,998 is a composite number.
4/199,999,999,998 =
(4 ÷ 2) / (199,999,999,998 ÷ 2) =
2/99,999,999,999
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.
4/199,999,999,998 =
22/(2 × 32 × 21,649 × 513,239) =
(22 ÷ 2) / ((2 × 32 × 21,649 × 513,239) ÷ 2) =
2/(32 × 21,649 × 513,239) =
2/99,999,999,999
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
2/99,999,999,999 =
2 ÷ 99,999,999,999 =
0.00000000002 ≈
0