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:
100 = 2 × 2 × 5 × 5 = 22 × 52
100 is a composite number.
4,000,000,078 = 2 × 239 × 8,368,201
4,000,000,078 is a composite number.
100/4,000,000,078 =
(100 ÷ 2) / (4,000,000,078 ÷ 2) =
50/2,000,000,039
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.
100/4,000,000,078 =
(22 × 52)/(2 × 239 × 8,368,201) =
((22 × 52) ÷ 2) / ((2 × 239 × 8,368,201) ÷ 2) =
(2 × 52)/(239 × 8,368,201) =
50/2,000,000,039
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
50/2,000,000,039 =
50 ÷ 2,000,000,039 =
0.000000025 ≈
0