Question

If an elevator goes 213 feet above ground in a building, it is said to be at +213 feet. If it moved to 23 feet below the ground, it is said to be -23 feet.

Answer 1

That's correct. When describing the position of an elevator (or any object) in a building, we use positive (+) values to indicate above-ground levels and negative (-) values to indicate below-ground levels. In this case:

If the elevator is 213 feet above ground, it's at +213 feet.

If it moves 23 feet below the ground, it's at -23 feet.

This convention is used to provide clear and standardized communication about the position of objects within a building.