The answer is:
4/25 is the same as saying 16/100 (you do it the easy way because its obvious). Thus, you have 16 over 100. That's 16 one-hundredths. .16 is your answer.
Or you simply divide the denominator into the numerator (the bottom into the top) like this: 4 divided by 25, which will give you the same answer: .16
Hope this helpes! :3