2. Write the mixed repeating (recurring) decimal number as a proper fraction.
0.636364 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 = 0.636364
Set up the second equation.
- Number of decimal places repeating: 1
Multiply both sides of the first equation by 101 = 10
y = 0.636364
10 × y = 10 × 0.636364
10 × y = 6.36364
Get the same number of decimal places as for y:
10 × y = 6.363644
Note: 6.363644 = 6.36364
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 = 6.363644 - 0.636364 ⇒
(10 - 1) × y = 6.363644 - 0.636364 ⇒
We now have a new equation:
9 × y = 5.72728
Solve for y in the new equation.
9 × y = 5.72728 ⇒
y = 5.72728/9
Let the result written as a fraction.
Now we can write the number as a fraction.
According to our first equation:
y = 0.636364
According to our calculations:
y = 5.72728/9
⇒ 0.636364 = 5.72728/9
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.
0.636364 = (5.72728 × 100,000)/(9 × 100,000)
0.636364 = 572,728/900,000
3. Reduce (simplify) the fraction above:
572,728/900,000
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).
572,728 = 23 × 13 × 5,507
900,000 = 25 × 32 × 55
Calculate the greatest (highest) common factor (divisor), GCF.
Multiply all the common prime factors by the lowest exponents.
GCF (23 × 13 × 5,507; 25 × 32 × 55) = 23
Divide both the numerator and the denominator by their GCF.
572,728/900,000 =
(23 × 13 × 5,507)/(25 × 32 × 55) =
((23 × 13 × 5,507) ÷ 23) / ((25 × 32 × 55) ÷ 23) =
(13 × 5,507)/(22 × 32 × 55) =
71,591/112,500