Put in a nutshell, a fraction is written in terms of two parts separated by a line in between: the number above the line is called the numerator and the number below the line is called the denominator. To solve this question, we can use the division method to get a decimal: simply divide the numerator 87 by the denominator 88 to get the decimal:

87 (numerator) ÷ 88 (denominator) = 0.99

That’s it! When you convert 87/88 to a decimal, 0.99 is your answer.