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 126 by the denominator 7 (which you can enter in any calculator):
126 (numerator) ÷ 7 (denominator) = 18
And finally, you get 18 as your answer when you convert 6 84/7 (or 126/7) to a decimal.