Question

How do you write $ - 1\dfrac{{13}}{{20}} $ as a decimal?

Answer 1

Hint: In order to obtain the decimal equivalent of the above mixed fraction , first convert this fraction into a regular fraction of the form $ \dfrac{p}{q} $ by using the rule $ a\dfrac{x}{y} = \dfrac{{ay + x}}{y} $ .Now we will try to make denominator in the form of 10 raised to power some $ n $ by multiplying and dividing the fraction with the number 5.S imply shift the decimal point of the numerator value towards left up to places equal to the exponent value of 10 to get your required result.

Complete step-by-step answer:
We are given a mixed fraction $ - 1\dfrac{{13}}{{20}} $ .
In order to write the decimal equivalent of the above mixed lets first convert this mixed fraction in the regular fraction of the form $ \dfrac{p}{q} $ by using the rule $ a\dfrac{x}{y} = \dfrac{{ay + x}}{y} $
In our case we have $ x = 13,a = - 1\,and\,y = 20 $
 $ - 1\dfrac{{13}}{{20}} = - \dfrac{{1\left( {20} \right) + 13}}{{20}} = - \dfrac{{20 + 13}}{{20}} = - \dfrac{{33}}{{20}} $
To convert any fraction into a decimal number, we try to make the denominator in the form of 10 raised to the power some $ n $ . Here we are multiply and divide the fraction with the $ 5 $ as $ 20 \times 5 = 100 $
 $
   = - \dfrac{{33}}{{20}} \times \dfrac{4}{4} \\
   = - \dfrac{{132}}{{100}} \\
   = - \dfrac{{132}}{{{{10}^2}}} \;
  $
Now shift the decimal point of the numerator up to the exponent value of $ 10 $ i.e. 2 towards left side
 $ = - 1.32 $
Therefore, the decimal equivalent of the fraction $ - 1\dfrac{{13}}{{20}} $ is equal to $ - 1.32 $
So, the correct answer is “ $ - 1.32 $ ”.

Note: 1. Cross-cross your result at least once.
2. To calculate fraction from the percentage , divide the given percentage value by 100
For example : We have to write $ 70\% $ into fraction
 $
   = \dfrac{{70}}{{100}} \\
   = \dfrac{7}{{10}} \;
  $
Or
 $ = 0.7 $
3. If the denominator of the fraction is not possible to make in the form of 10 raised to the power some $ n $ , then simply divide the fraction by long division to obtain the result.