2. Write the pure repeating (recurring) decimal number as a proper fraction.
0.09 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 = 0.09
Set up the second equation.
- Number of decimal places repeating: 2
Multiply both sides of the first equation by 102 = 100
y = 0.09
100 × y = 100 × 0.09
100 × y = 9.09
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 = 9.09 - 0.09 ⇒
(100 - 1) × y = 9.09 - 0.09 ⇒
We now have a new equation:
99 × y = 9
Solve for y in the new equation.
99 × y = 9 ⇒
y = 9/99
Let the result written as a fraction.
Now we can write the number as a fraction.
According to our first equation:
y = 0.09
According to our calculations:
y = 9/99
⇒ 0.09 = 9/99
3. Reduce (simplify) the fraction above:
9/99
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).
9 = 32
99 = 32 × 11
Calculate the greatest (highest) common factor (divisor), GCF.
Multiply all the common prime factors by the lowest exponents.
GCF (32; 32 × 11) = 32
Divide both the numerator and the denominator by their GCF.
9/99 =
32/(32 × 11) =
(32 ÷ 32) / ((32 × 11) ÷ 32) =
1/11