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:
1,256 = 2 × 2 × 2 × 157 = 23 × 157
1,256 is a composite number.
Written with exponents:
8,000,000 = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 5 × 5 × 5 × 5 × 5 × 5 = 29 × 56
8,000,000 is a composite number.
1,256/8,000,000 =
(1,256 ÷ 8) / (8,000,000 ÷ 8) =
157/1,000,000
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.
1,256/8,000,000 =
(23 × 157)/(29 × 56) =
((23 × 157) ÷ 23) / ((29 × 56) ÷ 23) =
157/(26 × 56) =
157/1,000,000
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
157/1,000,000 =
157 ÷ 1,000,000 =
0.000157 ≈
0