Answer:
Sea level is 0 meters. A cliff by the ocean is 12 meters above sea level. Around that area, the seafloor is 8 meters below sea level. How many meters is the top of the cliff to the seafloor?
How to solve:
8 below zero is -8
The expression 12 - (-8) is the same as the expression 12 + 8
12 + 8 = 20
20 meters