Answer :
This question is incomplete, here´s the complete question.
American Sign Language (ASL):
The sign for senior uses the same finger as the number...
Answer: 10 (ten)
Explanation:
In American sign language, to make the word "senior", meaning a student´s fourth year in college or university, we have to perform a double movement, which ends with the dominant flat hand taping the tip of the thumb of the stationary non-dominant hand.
The thumb is also used to make the number ten, by shaking it left and right while pointing upwards.