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:
45 = 3 × 3 × 5 = 32 × 5
45 is a composite number.
Written with exponents:
500,000,040 = 2 × 2 × 2 × 3 × 3 × 3 × 3 × 5 × 154,321 = 23 × 34 × 5 × 154,321
500,000,040 is a composite number.
45/500,000,040 =
(45 ÷ 45) / (500,000,040 ÷ 45) =
1/11,111,112
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.
45/500,000,040 =
(32 × 5)/(23 × 34 × 5 × 154,321) =
((32 × 5) ÷ (32 × 5)) / ((23 × 34 × 5 × 154,321) ÷ (32 × 5)) =
1/(23 × 32 × 154,321) =
1/11,111,112
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
1/11,111,112 =
1 ÷ 11,111,112 =
0.00000009 ≈
0