2. Write the mixed repeating (recurring) decimal number as a proper fraction.
0.039 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 = 0.039
Set up the second equation.
- Number of decimal places repeating: 1
Multiply both sides of the first equation by 101 = 10
y = 0.039
10 × y = 10 × 0.039
10 × y = 0.39
Get the same number of decimal places as for y:
10 × y = 0.399
Note: 0.399 = 0.39
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 = 0.399 - 0.039 ⇒
(10 - 1) × y = 0.399 - 0.039 ⇒
We now have a new equation:
9 × y = 0.36
Solve for y in the new equation.
9 × y = 0.36 ⇒
y = 0.36/9
Let the result written as a fraction.
Now we can write the number as a fraction.
According to our first equation:
y = 0.039
According to our calculations:
y = 0.36/9
⇒ 0.039 = 0.36/9
Get rid of the decimal places in the fraction above.
- Multiply the top and the bottom number by 100.
- 1 followed by as many 0-s as the number of digits after the decimal point.
0.039 = (0.36 × 100)/(9 × 100)
0.039 = 36/900
3. Reduce (simplify) the fraction above:
36/900
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).
36 = 22 × 32
900 = 22 × 32 × 52
Calculate the greatest (highest) common factor (divisor), GCF.
Multiply all the common prime factors by the lowest exponents.
GCF (22 × 32; 22 × 32 × 52) = 22 × 32
Divide both the numerator and the denominator by their GCF.
36/900 =
(22 × 32)/(22 × 32 × 52) =
((22 × 32) ÷ (22 × 32)) / ((22 × 32 × 52) ÷ (22 × 32)) =
1/52 =
1/25