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:
30 = 2 × 3 × 5
30 is a composite number.
4,000,000,042 = 2 × 19 × 3,361 × 31,319
4,000,000,042 is a composite number.
30/4,000,000,042 =
(30 ÷ 2) / (4,000,000,042 ÷ 2) =
15/2,000,000,021
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.
30/4,000,000,042 =
(2 × 3 × 5)/(2 × 19 × 3,361 × 31,319) =
((2 × 3 × 5) ÷ 2) / ((2 × 19 × 3,361 × 31,319) ÷ 2) =
(3 × 5)/(19 × 3,361 × 31,319) =
15/2,000,000,021
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
15/2,000,000,021 =
15 ÷ 2,000,000,021 =
0.0000000075 ≈
0