Convert the pure repeating (recurring) decimal number 0.31. Turn it into a reduced (simplified) proper fraction and write it as a percentage. Equivalent fractions calculator

Convert 0.31 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 (14).

0.31 ≈ 0.31313131313131


Multiply the number by 100/100.

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

0.31313131313131 =

0.31313131313131 × 100/100 =

(0.31313131313131 × 100)/100 =

31.313131313131/100 =

31.313131313131% ≈

31.31%

(rounded off to max. 2 decimal places)


  • In other words:
  • Approximate to the desired number of decimal places...
  • Multiply the number by 100...
  • ... And then add the percent sign, %
  • 0.31 ≈ 31.31%

» Convert fractions to percentages, online calculator


2. Write the pure repeating (recurring) decimal number as a proper fraction.

  • 0.31 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 = 0.31


Set up the second equation.

  • Number of decimal places repeating: 2

  • Multiply both sides of the first equation by 102 = 100


y = 0.31

100 × y = 100 × 0.31

100 × y = 31.31


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 = 31.31 - 0.31 ⇒

(100 - 1) × y = 31.31 - 0.31 ⇒

We now have a new equation:

99 × y = 31


Solve for y in the new equation.

99 × y = 31 ⇒

y = 31/99

Let the result written as a fraction.



Now we can write the number as a fraction.

According to our first equation:

y = 0.31

According to our calculations:

y = 31/99

⇒ 0.31 = 31/99


3. Reduce (simplify) the fraction above:
31/99
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 is a prime number, it cannot be factored into other prime factors

99 = 32 × 11


» 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.

But, the numerator and the denominator have no common factors.

GCF (31; 32 × 11) = 1


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


The numerator and the denominator are coprime numbers (no common prime factors, GCF = 1). So, the fraction cannot be reduced (simplified): irreducible fraction.


31/99 ~ 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 2.

31/99 = (31 × 2)/(99 × 2) = 62/198

Example 2. By expanding the fraction by 3.

31/99 = (31 × 3)/(99 × 3) = 93/297

  • Of course, the above fractions are reducing...
  • ... to the initial fraction: 31/99

» Reduce fractions and write them as decimal numbers and percentages


:: Final answer ::
Written in 3 different ways

As a reduced (simplified) positive proper fraction:
0.31 = 31/99

As a percentage:
0.31 ≈ 31.31%

As equivalent fractions:
0.31 = 31/99 = 62/198 = 93/297

More operations of this kind

0.32 = ? Convert the pure repeating (recurring) decimal number 0.32. Turn it into a reduced (simplified) proper fraction and 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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