2. Write the mixed repeating (recurring) decimal number as a proper fraction.
0.42857145 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 = 0.42857145
Set up the second equation.
- Number of decimal places repeating: 3
Multiply both sides of the first equation by 103 = 1,000
y = 0.42857145
1,000 × y = 1,000 × 0.42857145
1,000 × y = 428.57145
Get the same number of decimal places as for y:
1,000 × y = 428.57145145
Note: 428.57145145 = 428.57145
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.
1,000 × y - y = 428.57145145 - 0.42857145 ⇒
(1,000 - 1) × y = 428.57145145 - 0.42857145 ⇒
We now have a new equation:
999 × y = 428.14288
Solve for y in the new equation.
999 × y = 428.14288 ⇒
y = 428.14288/999
Let the result written as a fraction.
Now we can write the number as a fraction.
According to our first equation:
y = 0.42857145
According to our calculations:
y = 428.14288/999
⇒ 0.42857145 = 428.14288/999
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.
0.42857145 = (428.14288 × 100,000)/(999 × 100,000)
0.42857145 = 42,814,288/99,900,000
3. Reduce (simplify) the fraction above:
42,814,288/99,900,000
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).
42,814,288 = 24 × 11 × 243,263
99,900,000 = 25 × 33 × 55 × 37
Calculate the greatest (highest) common factor (divisor), GCF.
Multiply all the common prime factors by the lowest exponents.
GCF (24 × 11 × 243,263; 25 × 33 × 55 × 37) = 24
Divide both the numerator and the denominator by their GCF.
42,814,288/99,900,000 =
(24 × 11 × 243,263)/(25 × 33 × 55 × 37) =
((24 × 11 × 243,263) ÷ 24) / ((25 × 33 × 55 × 37) ÷ 24) =
(11 × 243,263)/(2 × 33 × 55 × 37) =
2,675,893/6,243,750