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:
162 = 2 × 3 × 3 × 3 × 3 = 2 × 34
162 is a composite number.
Written with exponents:
140,000 = 2 × 2 × 2 × 2 × 2 × 5 × 5 × 5 × 5 × 7 = 25 × 54 × 7
140,000 is a composite number.
162/140,000 =
(162 ÷ 2) / (140,000 ÷ 2) =
81/70,000
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.
162/140,000 =
(2 × 34)/(25 × 54 × 7) =
((2 × 34) ÷ 2) / ((25 × 54 × 7) ÷ 2) =
34/(24 × 54 × 7) =
81/70,000
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
81/70,000 =
81 ÷ 70,000 =
0.001157142857 ≈
0