2. Write the pure repeating (recurring) decimal number as an improper fraction.
3.14 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 = 3.14
Set up the second equation.
- Number of decimal places repeating: 2
Multiply both sides of the first equation by 102 = 100
y = 3.14
100 × y = 100 × 3.14
100 × y = 314.14
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 = 314.14 - 3.14 ⇒
(100 - 1) × y = 314.14 - 3.14 ⇒
We now have a new equation:
99 × y = 311
Solve for y in the new equation.
99 × y = 311 ⇒
y = 311/99
Let the result written as a fraction.
Now we can write the number as a fraction.
According to our first equation:
y = 3.14
According to our calculations:
y = 311/99
⇒ 3.14 = 311/99
3. Reduce (simplify) the fraction above:
311/99
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).
311 is a prime number, it cannot be factored into other prime factors
99 = 32 × 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 (311; 32 × 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.