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:
40 = 2 × 2 × 2 × 5 = 23 × 5
40 is a composite number.
500,000,070 = 2 × 3 × 5 × 16,666,669
500,000,070 is a composite number.
40/500,000,070 =
(40 ÷ 10) / (500,000,070 ÷ 10) =
4/50,000,007
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.
40/500,000,070 =
(23 × 5)/(2 × 3 × 5 × 16,666,669) =
((23 × 5) ÷ (2 × 5)) / ((2 × 3 × 5 × 16,666,669) ÷ (2 × 5)) =
22/(3 × 16,666,669) =
4/50,000,007
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
4/50,000,007 =
4 ÷ 50,000,007 =
0.00000008 ≈
0