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 143 by the denominator 5 (which you can enter in any calculator):
143 (numerator) ÷ 5 (denominator) = 28.6
And finally, you get 28.6 as your answer when you convert 17 58/5 (or 143/5) to a decimal.