Question

Jillian is looking up certain cities' elevations. She finds that New Orleans is 7 feet below sea level and that Oklahoma City is about 1000 feet above sea level. What number represents New Orleans's elevation

Answer 1

Above means positive
Below means negative

New Orleans is 7 feet 'Below", so elevation is -7 ft.

Answer 2

The number that represents New Orleans´s elevation is -7.

Explanation:

Given that New Orleans is 7 feet below sea level and Oklahoma 1000 feet above it, you have to consider that sea level is the reference value and it is consdired as cero. So

New Oreleans´s elevation = sea level - 7 ⇒ New Oreleans´s elevation = 0 - 7 ⇒New Oreleans´s elevation = -7.

Oklahoma elevation = sea level + 1000 ⇒Oklahoma elevation = 0 + 1000

⇒Oklahoma elevation = 1000.

Summarizing, New Orleans is 7 feet below sea level and the number that represents its elevation is -7.