2. Write the number as an improper fraction.
- 128.66 can be written as an improper fraction.
- An improper fraction = the numerator is larger than or equal to the denominator..
Write down the number divided by 1, as a fraction:
128.66 = 128.66/1
Turn the top number into a whole number.
- Multiply both the top and the bottom by the same number.
- This number is: 100.
- 1 followed by as many 0-s as the number of digits after the decimal point.
128.66/1 =
(128.66 × 100)/(1 × 100) =
12,866/100
3. Reduce (simplify) the fraction above:
12,866/100
to the lowest terms, to its simplest equivalent form, irreducible.
To reduce a fraction to the lowest terms divide the numerator and denominator by their greatest (highest) common factor (divisor), GCF.
Factor the numerator and denominator (prime factorization).
12,866 = 2 × 7 × 919
100 = 22 × 52
Calculate the greatest (highest) common factor (divisor), GCF.
Multiply all the common prime factors by the lowest exponents.
GCF (2 × 7 × 919; 22 × 52) = 2
Divide both the numerator and the denominator by their GCF.
12,866/100 =
(2 × 7 × 919)/(22 × 52) =
((2 × 7 × 919) ÷ 2) / ((22 × 52) ÷ 2) =
(7 × 919)/(2 × 52) =
6,433/50
4. The fraction is an improper one, rewrite it as a mixed number (mixed fraction):
- A mixed number = an integer number and a proper fraction, of the same sign.
- Example 1: 2 1/5; Example 2: - 1 3/7.
- A proper fraction = the numerator is smaller than the denominator.
6,433 ÷ 50 = 128, remainder = 33 ⇒
6,433 = 128 × 50 + 33 ⇒
6,433/50 =
(128 × 50 + 33) / 50 =
(128 × 50) / 50 + 33/50 =
128 + 33/50 =
128 33/50