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:
20,832 = 2 × 2 × 2 × 2 × 2 × 3 × 7 × 31 = 25 × 3 × 7 × 31
20,832 is a composite number.
Written with exponents:
49,995 = 3 × 3 × 5 × 11 × 101 = 32 × 5 × 11 × 101
49,995 is a composite number.
20,832/49,995 =
(20,832 ÷ 3) / (49,995 ÷ 3) =
6,944/16,665
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.
20,832/49,995 =
(25 × 3 × 7 × 31)/(32 × 5 × 11 × 101) =
((25 × 3 × 7 × 31) ÷ 3) / ((32 × 5 × 11 × 101) ÷ 3) =
(25 × 7 × 31)/(3 × 5 × 11 × 101) =
6,944/16,665
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
6,944/16,665 =
6,944 ÷ 16,665 =
0.416681668167 ≈
0.42