2. Write the mixed repeating (recurring) decimal number as a proper fraction.
0.6363639 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 = 0.6363639
Set up the second equation.
- Number of decimal places repeating: 1
Multiply both sides of the first equation by 101 = 10
y = 0.6363639
10 × y = 10 × 0.6363639
10 × y = 6.363639
Get the same number of decimal places as for y:
10 × y = 6.3636399
Note: 6.3636399 = 6.363639
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 = 6.3636399 - 0.6363639 ⇒
(10 - 1) × y = 6.3636399 - 0.6363639 ⇒
We now have a new equation:
9 × y = 5.727276
Solve for y in the new equation.
9 × y = 5.727276 ⇒
y = 5.727276/9
Let the result written as a fraction.
Now we can write the number as a fraction.
According to our first equation:
y = 0.6363639
According to our calculations:
y = 5.727276/9
⇒ 0.6363639 = 5.727276/9
Get rid of the decimal places in the fraction above.
- Multiply the top and the bottom number by 1,000,000.
- 1 followed by as many 0-s as the number of digits after the decimal point.
0.6363639 = (5.727276 × 1,000,000)/(9 × 1,000,000)
0.6363639 = 5,727,276/9,000,000
3. Reduce (simplify) the fraction above:
5,727,276/9,000,000
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).
5,727,276 = 22 × 32 × 23 × 6,917
9,000,000 = 26 × 32 × 56
Calculate the greatest (highest) common factor (divisor), GCF.
Multiply all the common prime factors by the lowest exponents.
GCF (22 × 32 × 23 × 6,917; 26 × 32 × 56) = 22 × 32
Divide both the numerator and the denominator by their GCF.
5,727,276/9,000,000 =
(22 × 32 × 23 × 6,917)/(26 × 32 × 56) =
((22 × 32 × 23 × 6,917) ÷ (22 × 32)) / ((26 × 32 × 56) ÷ (22 × 32)) =
(23 × 6,917)/(24 × 56) =
159,091/250,000