2. Write the mixed repeating (recurring) decimal number as an improper fraction.
2.54 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 = 2.54
Set up the second equation.
- Number of decimal places repeating: 1
Multiply both sides of the first equation by 101 = 10
y = 2.54
10 × y = 10 × 2.54
10 × y = 25.4
Get the same number of decimal places as for y:
10 × y = 25.44
Note: 25.44 = 25.4
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 = 25.44 - 2.54 ⇒
(10 - 1) × y = 25.44 - 2.54 ⇒
We now have a new equation:
9 × y = 22.9
Solve for y in the new equation.
9 × y = 22.9 ⇒
y = 22.9/9
Let the result written as a fraction.
Now we can write the number as a fraction.
According to our first equation:
y = 2.54
According to our calculations:
y = 22.9/9
⇒ 2.54 = 22.9/9
Get rid of the decimal places in the fraction above.
- Multiply the top and the bottom number by 10.
- 1 followed by as many 0-s as the number of digits after the decimal point.
2.54 = (22.9 × 10)/(9 × 10)
2.54 = 229/90
3. Reduce (simplify) the fraction above:
229/90
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).
229 is a prime number, it cannot be factored into other prime factors
90 = 2 × 32 × 5
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 (229; 2 × 32 × 5) = 1
The numerator and the denominator are coprime numbers (no common prime factors, GCF = 1). So, the fraction cannot be reduced (simplified): irreducible fraction.