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 11865 by the denominator 98 (which you can enter in any calculator):
11865 (numerator) ÷ 98 (denominator) = 121.07
And finally, you get 121.07 as your answer when you convert 120 105/98 (or 11865/98) to a decimal.