The easiest thing to do first is to make them like fractions. The first number where 5 and 8 meet, is 40. So it becomes 12 25/40 and 7 16/40. So we need to subtract 12 from 7 and that gives us 5. Then we subtract 16 from 25 and get 9. So our new number is 5 and 9/40. Thats the answer.