Multiplying the common ordinary fractions: - 15/18 × - 12/23 = ? The multiplication process explained. The result written: As a positive proper fraction (the numerator < the denominator). As a decimal number. As a percentage
- 15/18 × - 12/23 = ?
Simplify the operation
Rewrite the equivalent simplified operation:
Combine the signs of the fractions into a single one, placed in front of the expression. If the sign is + then it is usually not written.
The sign of a multiplication operation:
+ 1 × + 1 = + 1
+ 1 × - 1 = - 1
- 1 × - 1 = + 1
- 15/18 × - 12/23 =
15/18 × 12/23
Simplify the operation
Reduce (simplify) the fractions to their lowest terms equivalents:
To fully reduce a fraction, to the lowest terms equivalent: divide the numerator and denominator by their greatest common factor, GCF.
* By reducing the values of the numerators and the denominators of the fractions the calculations are easier to make.
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.
* In order to easily reduce a fraction, factor its numerator and denominator. This way all the common prime factors are easily identified and crossed out, without calculating the GCF.
15/18 =
(3 × 5)/(2 × 32) =
((3 × 5) ÷ 3)/((2 × 32) ÷ 3) =
(3 ÷ 3 × 5)/(2 × 32 ÷ 3) =
(1 × 5)/(2 × 3(2 - 1)) =
(1 × 5)/(2 × 31) =
(1 × 5)/(2 × 3) =
5/6
12/23 is already reduced to the lowest terms.
The numerator and denominator have no common prime factors.
Their prime factorization:
12 = 22 × 3
23 is a prime number (it cannot be factored into other prime factors)
Rewrite the equivalent simplified operation:
15/18 × 12/23 =
5/6 × 12/23
Perform the operation of calculating the fractions
Multiply the fractions:
1) Multiply the numerators, that is, all the numbers above the fractions bars, separately.
2) Multiply the denominators, that is, all the numbers below the fractions bars, separately.
* Factor all the numerators and all the denominators in order to easily reduce (simplify) the end fraction.
5/6 × 12/23 =
(5 × 12) / (6 × 23) =
(5 × 22 × 3) / (2 × 3 × 23) =
(22 × 3 × 5) / (2 × 3 × 23)
Fully reduce (simplify) the end fraction to its lowest terms equivalent:
Calculate the greatest common factor, GCF,
of the numerator and denominator of the fraction:
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.
To fully reduce a fraction, to the lowest terms equivalent: divide the numerator and denominator by their greatest common factor, GCF.
* To calculate the GCF, we need to factor the numerator and the 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 exponent (the lowest powers).
GCF (22 × 3 × 5; 2 × 3 × 23) = 2 × 3
Divide the numerator and the denominator by their GCF:
(22 × 3 × 5) / (2 × 3 × 23) =
((22 × 3 × 5) ÷ (2 × 3)) / ((2 × 3 × 23) ÷ (2 × 3)) =
(22 ÷ 2 × 3 ÷ 3 × 5)/(2 ÷ 2 × 3 ÷ 3 × 23) =
(2(2 - 1) × 1 × 5)/(1 × 1 × 23) =
(21 × 1 × 5)/(1 × 1 × 23) =
(2 × 1 × 5)/(1 × 1 × 23) =
(2 × 5)/23 =
10/23
Rewrite the fraction
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
10/23 =
10 ÷ 23 ≈
0.434782608696 ≈
0.43
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.
0.434782608696 =
0.434782608696 × 100/100 =
(0.434782608696 × 100)/100 =
43.478260869565/100 ≈
43.478260869565% ≈
43.48%
The final answer:
written in three ways
As a positive proper fraction:
(the numerator < the denominator)
- 15/18 × - 12/23 = 10/23
As a decimal number:
- 15/18 × - 12/23 ≈ 0.43
As a percentage:
- 15/18 × - 12/23 ≈ 43.48%
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.
Other similar operations
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