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:
3,108 = 2 × 2 × 3 × 7 × 37 = 22 × 3 × 7 × 37
3,108 is a composite number.
Written with exponents:
4,000 = 2 × 2 × 2 × 2 × 2 × 5 × 5 × 5 = 25 × 53
4,000 is a composite number.
3,108/4,000 =
(3,108 ÷ 4) / (4,000 ÷ 4) =
777/1,000
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.
3,108/4,000 =
(22 × 3 × 7 × 37)/(25 × 53) =
((22 × 3 × 7 × 37) ÷ 22) / ((25 × 53) ÷ 22) =
(3 × 7 × 37)/(23 × 53) =
777/1,000
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
777/1,000 =
777 ÷ 1,000 =
0.777 ≈
0.78