Question

The trail Paula runs begins at 27 feet below sea level and ends at 164 feet above sea level. What is the gain in elevation from the beginning to the end of the trail?

Answer 1

Initially, -27 feet elevated to +164 feet.

Keep in mind, the sign.
Below: negative ; Above: positive.

$164 - ( - 27) = 191$
At trail's end, Paula gained 191 feet of elevation.