A fraction is usually split into two parts: the first part is the number on top, called the numerator; and the second part is the number on the bottom, called the denominator. These are both separated by a line called the “divisor line”. We can use the division method help to solve this question: to get a decimal, simply divide the numerator 108 by the denominator 9 (which you can enter in any calculator):
108 (numerator) ÷ 9 (denominator) = 12
And finally, you get 12 as your answer when you convert 1 99/9 (or 108/9) to a decimal.