Answer:
2
Explanation:
The reason I said 2 is becasue you could go left and right. To the left of 0 is negitive numbers and to the right of 0 id positive numbers. So 10 units to the right of 0 is 10. Ten units to the left of zero is -10.
Hopefuly this helped you! Please tell me if I am Incorrect. That would be a great help.