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:
20 = 2 × 2 × 5 = 22 × 5
20 is a composite number.
Written with exponents:
500,000,025 = 3 × 5 × 5 × 7 × 952,381 = 3 × 52 × 7 × 952,381
500,000,025 is a composite number.
20/500,000,025 =
(20 ÷ 5) / (500,000,025 ÷ 5) =
4/100,000,005
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.
20/500,000,025 =
(22 × 5)/(3 × 52 × 7 × 952,381) =
((22 × 5) ÷ 5) / ((3 × 52 × 7 × 952,381) ÷ 5) =
22/(3 × 5 × 7 × 952,381) =
4/100,000,005
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
4/100,000,005 =
4 ÷ 100,000,005 =
0.00000004 ≈
0