Students were asked to find the difference between the positions of two sea creatures. An octopus was positioned at 180 feet below sea level. A narwhal was swimming 7 feet below sea level. Demarcus said you can find the difference with this expression: -7- (-180)

Maria said you can find the difference with this expression: -180 - 7
Who was correct, and why?

What is the difference between the positions of the two sea creatures?