: Divide: $40.32$ by $9.6$

Hint: In this problem, to find the required value first we will convert the given decimals into fraction. Then, we will simplify the obtained expression.

Complete step-by-step answer:
In this problem we have two decimals $40.32$ and $9.6$. Let us convert these decimals into fractions. In the number $40.32$ we can see that there are two digits to the right of the decimal. So, this number could be converted into fraction by dividing $100$. So, we can write $40.32 = \dfrac{{4032}}{{100}}$. Now the second number is $9.6$. We can see that there is only one digit to the right of the decimal. So, this number could be converted into fraction by dividing $10$. So, we can write $9.6 = \dfrac{{96}}{{10}}$. Now we have to divide the number $40.32$ by the number $9.6$. So, we can write
$40.32 \div 9.6 = \dfrac{{4032}}{{100}} \div \dfrac{{96}}{{10}}$
Let us rewrite the above expression. So, we get $40.32 \div 9.6 = \dfrac{{4032}}{{100}} \times \dfrac{{10}}{{96}}$.
Let us simplify the above expression. So, we get
$40.32 \div 9.6 = \dfrac{{4032}}{{96}} \times \dfrac{{10}}{{100}}$.
$ \Rightarrow 40.32 \div 9.6 = \dfrac{{42}}{{10}}$
$ \Rightarrow 40.32 \div 9.6 = 4.2$
Hence, the required answer is$4.2$.

Note: In fractions, the number above the line is called numerator and the number below the line is called denominator. For example, if the fraction is $\dfrac{{42}}{{10}}$ then $42$ is numerator and $10$ is denominator. The line which separates the numerator and the denominator represents the division. To convert the fraction $\dfrac{{75}}{{100}}$ into decimal, write the whole number $75$ with the decimal point $2$ spaces from the right because $100$ has $2$ zeros. That is, $\dfrac{{75}}{{100}} = 0.75$.