How do you write $\dfrac{4}{5}$ in percentage?

Hint: In order to calculate percentage of any fraction ,multiply fraction by 100 and find the result.

Formula Used:
$p = \dfrac{n}{d} \times 100$
Here p is the percentage , n/d is the fraction where n is the numerator and d is the denominator.

Complete step-by-step answer:
Let we have given a fraction in the form of $\dfrac{p}{q}$,where q is not equal to 0
Here, in this question we have given fraction as $\dfrac{4}{5}$
So, to calculate the percent from the fraction ,we have to first find the decimal value of fraction
$
   = \dfrac{4}{5} \\
   = 0.8 \\
 $
Now multiply the result with value 100
$
   = 0.8 \times 100 \\
$
Hence , the result is the fraction in percentage.

Alternate Method
If we don’t want to multiply 100 after dividing the fraction ,we have another way to calculate percentage i.e. by moving the decimal point 2 places in the right
For example: Calculate $\dfrac{1}{8}$ into percentage
Divide numerator by denominator =$0.125$
Now ,move the decimal point two places towards the right and add $\% $ at the end of the result.
$ = 12.5\% $

Note: 1. Don’t forget to place % sign at the end of the result.
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 we want to Increase a Number by y %:
Example:
On the off chance that a number is expanded by\[10{\text{ }}\% \], at that point it becomes 1.1 times of itself.
On the off chance that a number is expanded by 30 %, at that point it becomes 1.3 times of itself.
4. If we want to Decrease a Number by y %:
Example:
On the off chance that a number is diminished by 10 %, at that point it becomes 0.90 times of itself.
On the off chance that a number is diminished by 30 %, at that point it becomes 0.70 times of itself.