how do you change a number to a fraction

Well you can do what liveevillevi did, but....

Another (and better) way to do it is to find two numbers that when divided equal the original number.

So if i want to put 6 into a fraction, I can say 18/3.

you take the number and put it over 1. SO I have the number 45, and I want it in fraction form. It will be 45 over 1

That is probably what your teacher wants :)