A fraction is written in terms of two parts: the number on top is called the numerator and the number on the bottom is called the denominator. We can use the division method to solve this question. To get a decimal, simply divide the numerator 100 by the denominator 4:
100 (numerator) ÷ 4 (denominator) = 25
As a result, you get 25 as your answer when you convert 21 16/4 (or 100/4) to a decimal.