If you’re standing at the top of a mountain 6684 feet above sea level and there is a submarine at 350 feet below sea level how much higher is your elevation than the submarine?
I have attached an image to help you solve. Because you are 6684 feet above sea level (0) and then the sub is a further 350 feet below that, you have to add the two heights to find the TOTAL distance or how high you are above it.