So 16 over 8 would look like this:
16/8
Find a number that both numbers can be divided by and still be whole. For example, you could not use 3 here, because you would end up with a decimal. You could use two though. So use 2, and you get 8/4. Divide by 2 again, you have 4/2. Divide by 2 again, and you have 2/1, or 2.