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 12505 by the denominator 125 (which you can enter in any calculator):
12505 (numerator) ÷ 125 (denominator) = 100.04
And finally, you get 100.04 as your answer when you convert 99 130/125 (or 12505/125) to a decimal.