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:
90 = 2 × 3 × 3 × 5 = 2 × 32 × 5
90 is a composite number.
500,000,045 = 5 × 149 × 671,141
500,000,045 is a composite number.
90/500,000,045 =
(90 ÷ 5) / (500,000,045 ÷ 5) =
18/100,000,009
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.
90/500,000,045 =
(2 × 32 × 5)/(5 × 149 × 671,141) =
((2 × 32 × 5) ÷ 5) / ((5 × 149 × 671,141) ÷ 5) =
(2 × 32)/(149 × 671,141) =
18/100,000,009
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
18/100,000,009 =
18 ÷ 100,000,009 =
0.00000018 ≈
0