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:
168 = 2 × 2 × 2 × 3 × 7 = 23 × 3 × 7
168 is a composite number.
Written with exponents:
13,338 = 2 × 3 × 3 × 3 × 13 × 19 = 2 × 33 × 13 × 19
13,338 is a composite number.
168/13,338 =
(168 ÷ 6) / (13,338 ÷ 6) =
28/2,223
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.
168/13,338 =
(23 × 3 × 7)/(2 × 33 × 13 × 19) =
((23 × 3 × 7) ÷ (2 × 3)) / ((2 × 33 × 13 × 19) ÷ (2 × 3)) =
(22 × 7)/(32 × 13 × 19) =
28/2,223
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
28/2,223 =
28 ÷ 2,223 =
0.012595591543 ≈
0.01