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 140 by the denominator 18:
140 (numerator) ÷ 18 (denominator) = 7.78
As a result, you get 7.78 as your answer when you convert 3 86/18 (or 140/18) to a decimal.