2. Write the mixed repeating (recurring) decimal number as an improper fraction.
3.555555558 can be written as an improper fraction.
- The numerator is larger than or equal to the denominator.
Set up the first equation.
- Let y equal the decimal number:
y = 3.555555558
Set up the second equation.
- Number of decimal places repeating: 2
Multiply both sides of the first equation by 102 = 100
y = 3.555555558
100 × y = 100 × 3.555555558
100 × y = 355.5555558
Get the same number of decimal places as for y:
100 × y = 355.555555858
Note: 355.555555858 = 355.5555558
Subtract the first equation from the second one.
- Having the same number of decimal places ...
- The repeating pattern drops off by subtracting the two equations.
100 × y - y = 355.555555858 - 3.555555558 ⇒
(100 - 1) × y = 355.555555858 - 3.555555558 ⇒
We now have a new equation:
99 × y = 352.0000003
Solve for y in the new equation.
99 × y = 352.0000003 ⇒
y = 352.0000003/99
Let the result written as a fraction.
Now we can write the number as a fraction.
According to our first equation:
y = 3.555555558
According to our calculations:
y = 352.0000003/99
⇒ 3.555555558 = 352.0000003/99
Get rid of the decimal places in the fraction above.
- Multiply the top and the bottom number by 10,000,000.
- 1 followed by as many 0-s as the number of digits after the decimal point.
3.555555558 = (352.0000003 × 10,000,000)/(99 × 10,000,000)
3.555555558 = 3,520,000,003/990,000,000
3. Reduce (simplify) the fraction above:
3,520,000,003/990,000,000
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).
3,520,000,003 = 13 × 59 × 4,589,309
990,000,000 = 27 × 32 × 57 × 11
Calculate the greatest (highest) common factor (divisor), GCF.
Multiply all the common prime factors by the lowest exponents.
But, the numerator and the denominator have no common factors.
GCF (13 × 59 × 4,589,309; 27 × 32 × 57 × 11) = 1
The numerator and the denominator are coprime numbers (no common prime factors, GCF = 1). So, the fraction cannot be reduced (simplified): irreducible fraction.
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.
3,520,000,003 ÷ 990,000,000 = 3, remainder = 550,000,003 ⇒
3,520,000,003 = 3 × 990,000,000 + 550,000,003 ⇒
3,520,000,003/990,000,000 =
(3 × 990,000,000 + 550,000,003) / 990,000,000 =
(3 × 990,000,000) / 990,000,000 + 550,000,003/990,000,000 =
3 + 550,000,003/990,000,000 =
3 550,000,003/990,000,000