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:
1,287 = 3 × 3 × 11 × 13 = 32 × 11 × 13
1,287 is a composite number.
Written with exponents:
3,792 = 2 × 2 × 2 × 2 × 3 × 79 = 24 × 3 × 79
3,792 is a composite number.
1,287/3,792 =
(1,287 ÷ 3) / (3,792 ÷ 3) =
429/1,264
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.
1,287/3,792 =
(32 × 11 × 13)/(24 × 3 × 79) =
((32 × 11 × 13) ÷ 3) / ((24 × 3 × 79) ÷ 3) =
(3 × 11 × 13)/(24 × 79) =
429/1,264
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
429/1,264 =
429 ÷ 1,264 =
0.339398734177 ≈
0.34