Pre-Algebra Review Topic Using Signed Numbers to Represent Opposite Situations Topic Index | Algebra Index | Regents Exam Prep Center

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

 Numbers on a number line.
 Temperatures on a thermometer: Temperatures above zero degrees are positive (+10) and temperatures below zero degrees are negative (-10).
 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).

 Topic Index | Algebra Index | Regents Exam Prep Center Created by Donna Roberts