2. Write the number as an improper fraction.
- 408.58 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:
408.58 = 408.58/1
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.
408.58/1 =
(408.58 × 100)/(1 × 100) =
40,858/100
3. Reduce (simplify) the fraction above:
40,858/100
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).
40,858 = 2 × 31 × 659
100 = 22 × 52
Calculate the greatest (highest) common factor (divisor), GCF.
Multiply all the common prime factors by the lowest exponents.
GCF (2 × 31 × 659; 22 × 52) = 2
Divide both the numerator and the denominator by their GCF.
40,858/100 =
(2 × 31 × 659)/(22 × 52) =
((2 × 31 × 659) ÷ 2) / ((22 × 52) ÷ 2) =
(31 × 659)/(2 × 52) =
20,429/50
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.
20,429 ÷ 50 = 408, remainder = 29 ⇒
20,429 = 408 × 50 + 29 ⇒
20,429/50 =
(408 × 50 + 29) / 50 =
(408 × 50) / 50 + 29/50 =
408 + 29/50 =
408 29/50