Convert the pure repeating (recurring) decimal number 80.9. Turn it into a reduced (simplified) improper fraction, into a mixed number and write it as a percentage. Equivalent fractions calculator

Convert 80.9 into equivalent fractions and write it as a percentage value

1. Write the pure repeating (recurring) decimal number as a percentage.

Approximate to the desired number of decimal places.

80.9 ≈ 81


Multiply the number by 100/100.

  • The value of the number does not change when multiplying by 100/100.
  • Note: 100/100 = 1

81 =

81 × 100/100 =

(81 × 100)/100 =

8,100/100 =

8,100%


  • In other words:
  • Approximate to the desired number of decimal places...
  • Multiply the number by 100...
  • ... And then add the percent sign, %
  • 80.9 ≈ 8,100%

» Convert fractions to percentages, online calculator


2. Write the pure repeating (recurring) decimal number as an improper fraction.

  • 80.9 can be written as an improper fraction.

  • The numerator larger than or equal to the denominator.

Set up the first equation.

  • Let y equal the decimal number:

  • y = 80.9


Set up the second equation.

  • Number of decimal places repeating: 1

  • Multiply both sides of the first equation by 101 = 10


y = 80.9

10 × y = 10 × 80.9

10 × y = 809.9


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 = 809.9 - 80.9 ⇒

(10 - 1) × y = 809.9 - 80.9 ⇒

We now have a new equation:

9 × y = 729


Solve for y in the new equation.

9 × y = 729 ⇒

y = 729/9

Let the result written as a fraction.



Now we can write the number as a fraction.

According to our first equation:

y = 80.9

According to our calculations:

y = 729/9

⇒ 80.9 = 729/9


3. Reduce (simplify) the fraction above:
729/9
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).

729 = 36

9 = 32


» Prime factorization: break numbers down to prime factors, online calculator


Calculate the greatest (highest) common factor (divisor), GCF.

Multiply all the common prime factors by the lowest exponents.

GCF (36; 32) = 32


» Calculate the greatest (highest) common factor (divisor), GCF, online calculator


Divide both the numerator and the denominator by their GCF.

729/9 =

36/32 =

(36 ÷ 32) / (32 ÷ 32) =

34/1 =

81/1


Note:: 81/1 = 81

81/1 ~ Equivalent fractions.

  • The above fraction cannot be reduced.
  • That is, it has the smallest possible numerator and denominator.

  • By expanding it we can build up equivalent fractions.

  • Multiply the numerator & the denominator by the same number.


Example 1. By expanding the fraction by 5.

81/1 = (81 × 5)/(1 × 5) = 405/5

Example 2. By expanding the fraction by 10.

81/1 = (81 × 10)/(1 × 10) = 810/10

  • Of course, the above fractions are reducing...
  • ... to the initial fraction: 81/1

» Reduce fractions and write them as decimal numbers and percentages


:: Final answer ::
Written in 3 different ways

As a reduced (simplified) positive improper fraction:
80.9 = 81/1

As a percentage:
80.9 = 8,100%

As equivalent fractions:
80.9 = 81/1 = 405/5 = 810/10

More operations of this kind

81 = ? Convert the integer number 81. Turn it into a fraction and also write it as a percentage. Calculate other equivalent fractions to the decimal number, by expanding

Decimal numbers to fractions and percentages, calculator

Learn how to turn a decimal number into a fraction and a percentage. Steps.

1. How to write the number as a percentage:

  • Multiply the number by 100. Then add the percent sign, %.

2. How to write the number as a fraction:

  • Write down the number divided by 1, as a fraction.
  • Turn the top number into a whole number: multiply both the top and the bottom by the same number.
  • Reduce (simplify) the above fraction to the lowest terms, to its simplest equivalent form, irreducible. To reduce a fraction divide the numerator and the denominator by their greatest (highest) common factor (divisor), GCF.
  • If the fraction is an improper one, rewrite it as a mixed number (mixed fraction).
  • Calculate equivalent fractions. By expanding it we can build up equivalent fractions: multiply the numerator & the denominator by the same number.

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