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:
78,138 = 2 × 3 × 3 × 3 × 1,447 = 2 × 33 × 1,447
78,138 is a composite number.
500,019 = 3 × 13 × 12,821
500,019 is a composite number.
78,138/500,019 =
(78,138 ÷ 3) / (500,019 ÷ 3) =
26,046/166,673
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.
78,138/500,019 =
(2 × 33 × 1,447)/(3 × 13 × 12,821) =
((2 × 33 × 1,447) ÷ 3) / ((3 × 13 × 12,821) ÷ 3) =
(2 × 32 × 1,447)/(13 × 12,821) =
26,046/166,673
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
26,046/166,673 =
26,046 ÷ 166,673 =
0.156270061738 ≈
0.16