- 27/15 × 905/18 × 18/31 = ? Multiply the Common (Ordinary) Fractions, Online Calculator. Multiplication Operation Explained Step by Step

The numerators and the denominators of the fractions are multiplied separately

These fractions reduce each other:

They have numerators and denominators of equal values.


The fractions: 905/18 × 18/31 = 905/31

Rewrite the equivalent simplified operation:

- 27/15 × 905/18 × 18/31 =


- 27/15 × 905/31

Simplify the operation

Reduce (simplify) the fractions to their lowest terms equivalents:

  • A fully reduced (simplified) fraction is one with the smallest possible numerator and denominator, one that can no longer be reduced, and it is called an irreducible fraction.
  • * By reducing the values ​​of the numerators and denominators of fractions, subsequent calculations become easier to perform.
  • To reduce a fraction to the lowest terms equivalent divide its numerator and denominator by their greatest common factor, GCF.

  • To calculate the GCF, factor the numerator and denominator of the fraction into prime factors.
  • Then multiply all the common prime factors: if there are repeating prime factors we only take them once, and only the ones having the lowest exponents (the lowest powers).

The fraction: 27/15

The prime factorizations of the numerator and denominator:

27 = 33

15 = 3 × 5


GCF (27; 15) = 3


27/15 =

(27 ÷ 3)/(15 ÷ 3) =

9/5


Yet another method to reduce a fraction:

* To reduce a fraction without calculating the GCF: factor its numerator and denominator, then all the common prime factors are easily identified and crossed out.


27/15 =


33/(3 × 5) =


(33 ÷ 3)/((3 × 5) ÷ 3) =


(33 ÷ 3)/(3 ÷ 3 × 5) =


3(3 - 1)/(1 × 5) =


32/(1 × 5) =


9/5


The fraction: 905/31

905/31 is already reduced to the lowest terms.

The numerator and denominator have no common prime factors.


The prime factorizations of the numerator and denominator:

905 = 5 × 181

31 is a prime number (it cannot be factored into other prime factors)


GCF (905; 31) = 1



Rewrite the equivalent simplified operation:

- 27/15 × 905/31 =


- 9/5 × 905/31

Perform the operation of calculating the fractions

Multiply the fractions:

Multiply the numerators, that is, all the numbers above fractions bars, separately.

Multiply the denominators, that is, all the numbers below fractions bars, separately.


* Factor all the numerators and all the denominators in order to easily reduce (simplify) the end fraction.

External link » Factor (decompose) composite numbers into prime factors, online calculator


- 9/5 × 905/31 =


- (9 × 905) / (5 × 31) =


- (32 × 5 × 181) / (5 × 31)

Reduce (simplify) the end fraction to its lowest terms equivalent:

Calculate the greatest common factor, GCF,
of the numerator and denominator of the fraction:

  • To reduce a fraction to the lowest terms equivalent divide its numerator and denominator by their greatest common factor, GCF.

  • To calculate the GCF, factor the numerator and denominator of the fraction into prime factors.
  • Then multiply all the common prime factors: if there are repeating prime factors we only take them once, and only the ones having the lowest exponents (the lowest powers).

GCF (32 × 5 × 181; 5 × 31) = 5



Divide the numerator and the denominator by their GCF:

- (32 × 5 × 181) / (5 × 31) =


- ((32 × 5 × 181) ÷ 5) / ((5 × 31) ÷ 5) =


- (32 × 5 ÷ 5 × 181)/(5 ÷ 5 × 31) =


- (32 × 1 × 181)/(1 × 31) =


- (32 × 181)/31 =


- (9 × 181)/31 =


- 1,629/31

Rewrite the fraction

As a mixed number (also called a mixed fraction):

  • A mixed number: a whole number and a proper fraction, both having the same sign.
  • A proper fraction: the value of the numerator is smaller than the value of the denominator.
  • Divide the numerator by the denominator and write down the quotient and the remainder of the division, as shown below:

- 1,629 ÷ 31 = - 52 and the remainder = - 17 ⇒


- 1,629 = - 52 × 31 - 17 ⇒


- 1,629/31 =


( - 52 × 31 - 17)/31 =


( - 52 × 31)/31 - 17/31 =


- 52 - 17/31 =


- 52 17/31

As a decimal number:

Simply divide the numerator by the denominator, without a remainder, as shown below:


- 52 - 17/31 =


- 52 - 17 ÷ 31 ≈


- 52.548387096774 ≈


- 52.55

As a percentage:

  • A percentage value p% is equal to the fraction: p/100, for any decimal number p. So, we need to change the form of the number calculated above, to show a denominator of 100.
  • To do that, multiply the number by the fraction 100/100.
  • The value of the fraction 100/100 = 1, so by multiplying the number by this fraction the result is not changing, only the form.

- 52.548387096774 =


- 52.548387096774 × 100/100 =


( - 52.548387096774 × 100)/100 =


- 5,254.838709677419/100


- 5,254.838709677419% ≈


- 5,254.84%


The final answer:
written in four ways

As a negative improper fraction:
(the numerator >= the denominator)
- 27/15 × 905/18 × 18/31 = - 1,629/31

As a mixed number (also called a mixed fraction):
- 27/15 × 905/18 × 18/31 = - 52 17/31

As a decimal number:
- 27/15 × 905/18 × 18/31 ≈ - 52.55

As a percentage:
- 27/15 × 905/18 × 18/31 ≈ - 5,254.84%

How are the numbers being written on our website: comma ',' is used as a thousands separator; point '.' used as a decimal separator; numbers rounded off to max. 12 decimals (if the case). The set of the used symbols on our website: '/' the fraction bar; ÷ dividing; × multiplying; + plus (adding); - minus (subtracting); = equal; ≈ approximately equal.

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