How do you write $\dfrac{2}{5}$ as decimal?

Hint: From the given question we have to write the decimal of $\dfrac{2}{5}$. To find the decimal of $\dfrac{2}{5}$ , the easiest way is to multiply it until the denominator is $10$. As decimals are written in a tens system (with a tenths, hundredths, thousandths, etc. place), we can easily write fractions with a denominator of $10$ as decimals. The way to make the denominator ten is to multiply both the numerator and denominator by $\dfrac{10}{\text{denominator}}$. By this we can find the decimal of $\dfrac{2}{5}$.

Complete step-by-step solution:
From the question given we have to find the decimal of
$\Rightarrow \dfrac{2}{5}$
As we know that to write the decimal, we have to make the denominator $10$.
To get the decimal for the above fraction, we have to convert the denominator as a power of 10. We know that fractions with denominators as power of 10 can be converted to decimals very easily. So, here, we have to make the denominator $10$.
The way to make the denominator ten is to multiply both the numerator and denominator by

$\Rightarrow \dfrac{10}{\text{denominator}}$

Here in this case, we have to multiply both the numerator and denominator by

$\Rightarrow \dfrac{10}{5}$

By multiplying we will get,

$\Rightarrow \dfrac{2}{5}\left( \dfrac{\dfrac{10}{5}}{\dfrac{10}{5}} \right)$

$\Rightarrow \dfrac{2}{5}\left( \dfrac{2}{2} \right)$

$\Rightarrow 0.4$

Therefore, the decimal of $\dfrac{2}{5}$ is $0.4$.

Note: Students should know the easiest method to solve or convert the given number into the decimal. Students can also solve this by using long division. Students should make the denominator as $\left( 10,100,100.. \right)$ by this they can write the decimal forms very easily.