To find how much lower check. One is then check .5, you would subtract the absolute values of both negative integers. Think of it as finding the distance between -188 and -57 on a number line. Checkpoint one is 131 feet lower than checkpoint five. To find the altitude of the top Hill you need to think of where you are starting and how far you are moving. If you start at -188, it would take 188 feet to get back to zero. This would be the distance from zero to -188 or the absolute value of -188. From zero you then would go up to 274 more feet putting you at +274 feet for the altitude. I subtracted 462 minus the 188 it took to get back to zero to get the 274 feet.
