2. Write the mixed repeating (recurring) decimal number as a proper fraction.
0.63636365 can be written as a proper fraction.
- The numerator is smaller than the denominator.
Set up the first equation.
- Let y equal the decimal number:
y = 0.63636365
Set up the second equation.
- Number of decimal places repeating: 1
Multiply both sides of the first equation by 101 = 10
y = 0.63636365
10 × y = 10 × 0.63636365
10 × y = 6.3636365
Get the same number of decimal places as for y:
10 × y = 6.36363655
Note: 6.36363655 = 6.3636365
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.
10 × y - y = 6.36363655 - 0.63636365 ⇒
(10 - 1) × y = 6.36363655 - 0.63636365 ⇒
We now have a new equation:
9 × y = 5.7272729
Solve for y in the new equation.
9 × y = 5.7272729 ⇒
y = 5.7272729/9
Let the result written as a fraction.
Now we can write the number as a fraction.
According to our first equation:
y = 0.63636365
According to our calculations:
y = 5.7272729/9
⇒ 0.63636365 = 5.7272729/9
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.
0.63636365 = (5.7272729 × 10,000,000)/(9 × 10,000,000)
0.63636365 = 57,272,729/90,000,000
3. Reduce (simplify) the fraction above:
57,272,729/90,000,000
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).
57,272,729 is a prime number, it cannot be factored into other prime factors
90,000,000 = 27 × 32 × 57
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 (57,272,729; 27 × 32 × 57) = 1
The numerator and the denominator are coprime numbers (no common prime factors, GCF = 1). So, the fraction cannot be reduced (simplified): irreducible fraction.