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:
620 = 2 × 2 × 5 × 31 = 22 × 5 × 31
620 is a composite number.
Written with exponents:
39,999,996 = 2 × 2 × 3 × 3 × 239 × 4,649 = 22 × 32 × 239 × 4,649
39,999,996 is a composite number.
620/39,999,996 =
(620 ÷ 4) / (39,999,996 ÷ 4) =
155/9,999,999
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.
620/39,999,996 =
(22 × 5 × 31)/(22 × 32 × 239 × 4,649) =
((22 × 5 × 31) ÷ 22) / ((22 × 32 × 239 × 4,649) ÷ 22) =
(5 × 31)/(32 × 239 × 4,649) =
155/9,999,999
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
155/9,999,999 =
155 ÷ 9,999,999 =
0.000015500002 ≈
0