Simon and his team are preparing to climb my. Sinclair. Base camp is located 21 feet below sea level. Mt. Sinclair is 490 feet above sea level. on the 1st stage of their climb, they will camp at a ranger station located 124 feet above sealevel. The next day they all hike the rest of the way to the peak. What is the difference in elevation in feet from their base camp to the ranger station?

2 answers

21 + 124 = ?
or, more generally,
124 - (-21) = ?

If a < b, the difference between a and b is b-a.