How do you convert $\dfrac{{21}}{4}$ into a decimal and percent?

Hint: In this question, we have been given a fractional number and we are asked to convert the given fractional number into the decimal number and also, we have been asked to convert the given fractional number into the percent. To convert into percent, we need to use the decimal number of the given fractional number.

Complete step-by-step solution:
Given the fractional number as $\dfrac{{21}}{4}$ .
To convert into a decimal, we will just simply do the division.
Now, the given fractional number can also be written as $\dfrac{{21}}{4} = \dfrac{{20 + 1}}{4}$
Here, we have written the numerator as the addition of two numbers and the denominator is the same. So, we split the fractions, we get
$ \Rightarrow \dfrac{{21}}{4} = \dfrac{{20 + 1}}{4} = \dfrac{{20}}{4} + \dfrac{1}{4}$
$ \Rightarrow \dfrac{{21}}{4} = \dfrac{{20}}{4} + \dfrac{1}{4} - - - - - \left( 1 \right)$
Let’s cancel the term $\dfrac{{20}}{4}$ in the left-hand side of equation (1), we get,
$ \Rightarrow \dfrac{{21}}{4} = 5 + \dfrac{1}{4}$
Now, cancel the term $\dfrac{1}{4}$ in the right-hand side of equation (1), we get,
$ \Rightarrow \dfrac{{21}}{4} = 5 + 0.25$ , let’s add both the sides, we get,
$ \Rightarrow \dfrac{{21}}{4} = 5.25$
Therefore, we converted the given fractional number into a decimal number.
Now, our work is to convert this decimal number into a percent. For that, we just need to multiply the decimal number by $100$.
$ \Rightarrow 5.25 \times 100\% = 525\% $

The given number in decimal form is 5.25 and in percentage form is 525%.

Additional Information: A fractional number is used to represent a part of a whole. Fractions consist of two numbers: a numerator and a denominator. A decimal number is used to represent a non – whole number where a decimal point is used followed by digits that represent a value that is smaller than one.

Note: The easiest way to convert a fraction to a decimal is to divide the numerator by the denominator. In this problem, we have done this by splitting the fractions into two. The resulting answer will be the value of the fraction expressed as a decimal number. We converted a decimal to a percentage by multiplying the decimal value by $100$ and adding the sign of $\% $ .