Is a temperature of -11 degrees warmer or colder than a temperature of -15 degrees? *
Is an elevation of -10 feet closer or farther from the surface of the ocean than an elevation of -8 feet? *
It was 8 degrees at nightfall. The temperature dropped 10 degrees by midnight. What was the temperature at midnight? *
A diver is 25 feet below sea level. After he swims up 15 feet toward the surface, what is his elevation? *

A whale is at the surface of the ocean to breathe. The whale swims down 300 feet to feed. The whale is now 300 feet below sea level. *