Positive and negative numbers can represent or describe
 many different situations which demonstrate the
concept of opposites:

	Numbers on a number line. + 3 is 3 units to the right of 0, while -3 is 3 units to the left of 0.
	Temperatures on a thermometer: Temperatures above zero degrees are positive (+10º) and temperatures below zero degrees are negative (-10º).
	Sports scores: If your favorite football team gained 4 yards during the big game, it could be represented by +4.   Should your team lose 4 yards, it could be represented by –4.
	Weight gain and loss: Sam gained 8 pounds while on a Caribbean cruise (+8), but lost the 8 pounds after he returned home (-8).
	Geography: A location in Death Valley has an elevation of -282 feet (which is below sea level), while a location near Coffin Peak has an elevation of +282 feet (which is above seal level).
	Altitude: An airplane leaves the airport and climbs to an altitude (height) of 2500 feet (+2500). To land, the plane must lose 2500 feet of altitude (-2500).
	Profit and loss: A candy store lost $28,400 (-$28,400) the first year of business but recovered the amount (+$28,400) the second year.
	Recorded time: When referring to historical times, 2000 years BC (-2000) can be compared to 2000 years AD (+2000).
	Elevator movement: The elevator went up 15 floors (+15), and then went down 15 floors (-15).
	Checking Accounts: When the balance in your checking account is +$650, you have $650 available to spend. When your balance is -$650, you are in debt, and you owe the bank $650.