MATH 2.1 : Absolute Value of a Number

• The absolute value of a real number is its distance from zero on the number line.
• What is the absolute value of -2?

  2
• How can you determine the absolute value of a negative number using a number line?

  You can see that the number is a certain distance away from zero, which is positive.
• If you evaluate |–2|, what does it represent in terms of distance from zero?

  It represents a distance of 2 units from zero.
• What does the expression |–2| illustrate about absolute values?

  It illustrates that absolute values are always non-negative and represent distance from zero.
• The absolute value of a number is the distance of a number from zero. It is usually denoted by the symbol |𝑥|, where 𝑥 is any real number.
• How many floors did the elevator climb before going underground?

  15 floors
• What integer is assigned to the ground floor in the elevator problem?

  0
• What is the absolute value assigned for the ascent to the 15th floor?

  |15|
• How do you represent the descent from the 15th floor to two floors underground using absolute values?


  |–15| + |–2|
• What is the absolute value assigned for the ascent from two floors underground to the ground floor?

  |2|
• What are the steps to calculate the total distance traveled by the elevator?


  1. Assign integers for each floor (0 for ground floor).
  2. Calculate absolute values for each ascent and descent:

  • From ground to 15th floor: |15|
  • From 15th floor to two floors underground: |–15| + |–2|
  • From two floors underground to ground: |2|

  1. Add all absolute values to find total distance:

  • Total distance = |15| + |–15| + |–2| + |–2| = 34 floors
• What is the total distance traveled by the elevator after all ascents and descents?

  34 floors