Use a number line and count backwards from 1 to -9. So on the number line, as you move from 1 to 0 to -1, etc, count how many total jumps you made and that will give you your answer.
For instance, if you go from 7 to 4, your first jump is 7 to 6. The second one is from 6 to 5. Third jump would be 5 to 4. So how many jumps did you make? 3! So 7 - 4 = 3. It's the same concept but your numbers are different. That's why drawing things out is very helpful.