Answer:
You owuld have to count the difference between the numbers.
Explanation:
to find the distance between 1 to ten:
1_|__|_|_|__|__|__|__|_10
The addititive inverse would be 9 since there are nine lines before it gets to ten. So the distance between 1 and 10 would be 9.
(Sorry if this doesn't make sense, comment and I'll try to explain any other questions)