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:
140 = 2 × 2 × 5 × 7 = 22 × 5 × 7
140 is a composite number.
Written with exponents:
40,068 = 2 × 2 × 3 × 3 × 3 × 7 × 53 = 22 × 33 × 7 × 53
40,068 is a composite number.
140/40,068 =
(140 ÷ 28) / (40,068 ÷ 28) =
5/1,431
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.
140/40,068 =
(22 × 5 × 7)/(22 × 33 × 7 × 53) =
((22 × 5 × 7) ÷ (22 × 7)) / ((22 × 33 × 7 × 53) ÷ (22 × 7)) =
5/(33 × 53) =
5/1,431
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
5/1,431 =
5 ÷ 1,431 =
0.003494060098 ≈
0