Question

how do you write 12/75 as a decimal

Answer 1

$\frac{12}{75} = 0.16$

Answer 2

Every fraction is a short way to write a division problem. 
It means "the top number divided by the bottom number".
In order to write the decimal, do the division.  Divide the
numerator (top number) by the denominator (bottom number).
The quotient is the decimal equivalent of the fraction.

' 12/75 ' means "twelve divided by seventy-five". 
Pick up your pencil or your calculator, and divide  12  by  75 .
The quotient is 0.16 .