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 87 by the denominator 45 (which you can enter in any calculator):
87 (numerator) ÷ 45 (denominator) = 1.93
And finally, you get 1.93 as your answer when you convert 1 42/45 (or 87/45) to a decimal.