Answer:
164
Step-by-step explanation:
Checkpoint 2= -187
Checkpoint 1= -23
The negatives mean how much lower they are from the surface.
To find "how much lower," we need to subtract -23 from -187.
-187-(-23) is the same as -187+23 (2 negatives=1 positive)
-187+23= -164.
However, it's not negative in the answer because by asking how much lower, we don't need to have a negative. "How much lower" is a distance, and a distance is always positive.
