When can you use it in real life?
http://www.streetsblog.org
Distances in real life: suppose you go three blocks east, then six blocks west, then eleven blocks east again. Now we can ask two questions: Where are you relative to where you started? This requires us to retain the sign information, and is not answered by the absolute value. The other obvious question is "How far did you go?" Now every student in your
class should add 3 + 6 + 11, each of them doing at least one absolute value operation in their mind (for the -6).
Of course distances are useful in many real world applications, such as navigation and transport ("Do we have enough fuel to get
there AND back?"), architecture, engineering and science, and sports ("How many consecutive 15-yard penalties can the referees
call before it becomes half-the-distance-to-the goal-line", if we start at midfield?").
Source: http://mathforum.org/library/drmath/view/57177.html
Of course distances are useful in many real world applications, such as navigation and transport ("Do we have enough fuel to get
there AND back?"), architecture, engineering and science, and sports ("How many consecutive 15-yard penalties can the referees
call before it becomes half-the-distance-to-the goal-line", if we start at midfield?").
Source: http://mathforum.org/library/drmath/view/57177.html