Answer:
Positive number: Elevation of a mountain above sea level, growth of a plant, money saved. Negative number: Temperature colder than 0.
Explanation:
Elevation of a mountain that is above sea level is positive since it isn't below sea level, which would be negative, you are increasing as you go up. Growth of a plant is positive since it isn't growing shorter. Money saved since you aren't spending it. Temperature colder than 0 because that is when the negative numbers start to occur.