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:
1,666,668 = 2 × 2 × 3 × 138,889 = 22 × 3 × 138,889
1,666,668 is a composite number.
Written with exponents:
4,000,000 = 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 5 × 5 × 5 × 5 × 5 × 5 = 28 × 56
4,000,000 is a composite number.
1,666,668/4,000,000 =
(1,666,668 ÷ 4) / (4,000,000 ÷ 4) =
416,667/1,000,000
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.
1,666,668/4,000,000 =
(22 × 3 × 138,889)/(28 × 56) =
((22 × 3 × 138,889) ÷ 22) / ((28 × 56) ÷ 22) =
(3 × 138,889)/(26 × 56) =
416,667/1,000,000
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
416,667/1,000,000 =
416,667 ÷ 1,000,000 =
0.416667 ≈
0.42