2. Write the mixed repeating (recurring) decimal number as a proper fraction.
0.31843 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 = 0.31843
Set up the second equation.
- Number of decimal places repeating: 2
Multiply both sides of the first equation by 102 = 100
y = 0.31843
100 × y = 100 × 0.31843
100 × y = 31.843
Get the same number of decimal places as for y:
100 × y = 31.84343
Note: 31.84343 = 31.843
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 = 31.84343 - 0.31843 ⇒
(100 - 1) × y = 31.84343 - 0.31843 ⇒
We now have a new equation:
99 × y = 31.525
Solve for y in the new equation.
99 × y = 31.525 ⇒
y = 31.525/99
Let the result written as a fraction.
Now we can write the number as a fraction.
According to our first equation:
y = 0.31843
According to our calculations:
y = 31.525/99
⇒ 0.31843 = 31.525/99
Get rid of the decimal places in the fraction above.
- Multiply the top and the bottom number by 1,000.
- 1 followed by as many 0-s as the number of digits after the decimal point.
0.31843 = (31.525 × 1,000)/(99 × 1,000)
0.31843 = 31,525/99,000
3. Reduce (simplify) the fraction above:
31,525/99,000
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).
31,525 = 52 × 13 × 97
99,000 = 23 × 32 × 53 × 11
Calculate the greatest (highest) common factor (divisor), GCF.
Multiply all the common prime factors by the lowest exponents.
GCF (52 × 13 × 97; 23 × 32 × 53 × 11) = 52
Divide both the numerator and the denominator by their GCF.
31,525/99,000 =
(52 × 13 × 97)/(23 × 32 × 53 × 11) =
((52 × 13 × 97) ÷ 52) / ((23 × 32 × 53 × 11) ÷ 52) =
(13 × 97)/(23 × 32 × 5 × 11) =
1,261/3,960