Ashley is diving in the ocean. She wants to reach a coral reef that is 60 feet below sea level; that is, the reef’s elevation is -60 feet. She decides to safely descend to the reef from the ocean’s surface in increments of 10 feet. Answer the following questions to learn more about Ashley’s rate of descent. Ashley dives in increments of 10 feet. What rational number represents diving 10 feet below sea level?