1. Write the mixed repeating (recurring) decimal number as a percentage.
Approximate to the desired number of decimal places (14).
66.6666667 ≈ 66.66666676767677
Multiply the number by 100/100.
- The value of the number does not change when multiplying by 100/100.
- Note: 100/100 = 1
66.66666676767677 =
66.66666676767677 × 100/100 =
(66.66666676767677 × 100)/100 =
6,666.666676767677/100 =
6,666.666676767677% ≈
6,666.67%
(rounded off to max. 2 decimal places)
- In other words:
- Approximate to the desired number of decimal places...
- Multiply the number by 100...
- ... And then add the percent sign, %
- 66.6666667 ≈ 6,666.67%
2. Write the mixed repeating (recurring) decimal number as an improper fraction.
66.6666667 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 = 66.6666667
Set up the second equation.
- Number of decimal places repeating: 2
Multiply both sides of the first equation by 102 = 100
y = 66.6666667
100 × y = 100 × 66.6666667
100 × y = 6,666.66667
Get the same number of decimal places as for y:
100 × y = 6,666.6666767
Note: 6,666.6666767 = 6,666.66667
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 = 6,666.6666767 - 66.6666667 ⇒
(100 - 1) × y = 6,666.6666767 - 66.6666667 ⇒
We now have a new equation:
99 × y = 6,600.00001
Solve for y in the new equation.
99 × y = 6,600.00001 ⇒
y = 6,600.00001/99
Let the result written as a fraction.
Now we can write the number as a fraction.
According to our first equation:
y = 66.6666667
According to our calculations:
y = 6,600.00001/99
⇒ 66.6666667 = 6,600.00001/99
Get rid of the decimal places in the fraction above.
- Multiply the top and the bottom number by 100,000.
- 1 followed by as many 0-s as the number of digits after the decimal point.
66.6666667 = (6,600.00001 × 100,000)/(99 × 100,000)
66.6666667 = 660,000,001/9,900,000
3. Reduce (simplify) the fraction above:
660,000,001/9,900,000
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).
660,000,001 = 41 × 103 × 373 × 419
9,900,000 = 25 × 32 × 55 × 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 (41 × 103 × 373 × 419; 25 × 32 × 55 × 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.
660,000,001 ÷ 9,900,000 = 66, remainder = 6,600,001 ⇒
660,000,001 = 66 × 9,900,000 + 6,600,001 ⇒
660,000,001/9,900,000 =
(66 × 9,900,000 + 6,600,001) / 9,900,000 =
(66 × 9,900,000) / 9,900,000 + 6,600,001/9,900,000 =
66 + 6,600,001/9,900,000 =
66 6,600,001/9,900,000