11.25 is 11 1/4 because if you were to do 1 divided by 4, you would find that the answer is 0.25. But if you need an improper fraction, you would get 45/4 because if you were to put 11 times 4, you would get 44, and 44+1=45. Then you put that on the numerator spot, and you will get 45/4 for improper fraction.