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:
5,156 = 2 × 2 × 1,289 = 22 × 1,289
5,156 is a composite number.
Written with exponents:
20,000 = 2 × 2 × 2 × 2 × 2 × 5 × 5 × 5 × 5 = 25 × 54
20,000 is a composite number.
5,156/20,000 =
(5,156 ÷ 4) / (20,000 ÷ 4) =
1,289/5,000
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.
5,156/20,000 =
(22 × 1,289)/(25 × 54) =
((22 × 1,289) ÷ 22) / ((25 × 54) ÷ 22) =
1,289/(23 × 54) =
1,289/5,000
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
1,289/5,000 =
1,289 ÷ 5,000 =
0.2578 ≈
0.26