Instructions
Read the explanation of absolute value below. Then, work through the problems in each section. Remember, absolute value is all about distance from zero!
Part 1: What is Absolute Value?
The absolute value of a number is its distance from zero on a number line. Since distance is always a positive value (you can't travel a negative distance!), the absolute value of a number is always positive or zero.
Think of it like taking steps. If you are standing at zero, taking 8 steps forward (+8) and taking 8 steps backward (-8) both result in you being 8 steps away from where you started.
The symbol for absolute value is two vertical bars: | |.
- So, we would write |-8| = 8, which is read as "The absolute value of negative eight is eight."
- We would also write |8| = 8, which is read as "The absolute value of eight is eight."
Part 2: Find the Value
Solve the following absolute value expressions.
- |-12| =
- |35| =
- |0| =
- |-250| =
- |19.5| =
- |-3/4| =
Part 3: Compare the Values
Fill in the blank circle with <, >, or = to make the statement true.
- |-15| ◯ |15|
- |-20| ◯ 19
- 8 ◯ |-9|
- |-5| + |3| ◯ |-8|
- |12 - 7| ◯ |-5|
- |-100| ◯ |50| + |50|
Part 4: Solving for a Variable
Find all possible values for x in the equations below. Hint: There might be more than one answer for some questions!
- |x| = 22
- |x| = 5
- |x| = -10
- |x| + 3 = 14
Part 5: Brain Challenge!
Read the scenario and answer the question.
A submarine is exploring the ocean. It starts at sea level (0 meters). It first descends to -150 meters. Later, it ascends to a position of -95 meters. At which point, -150 m or -95 m, was the submarine farther from sea level?
Answer:
Answer Key
Part 2: Find the Value
- 12
- 35
- 0
- 250
- 19.5
- 3/4
Part 3: Compare the Values
- |-15| = |15| (15 = 15)
- |-20| > 19 (20 > 19)
- 8 < |-9| (8 < 9)
- |-5| + |3| = |-8| (5 + 3 = 8)
- |12 - 7| = |-5| (|5| = |-5|, so 5 = 5)
- |-100| = |50| + |50| (100 = 50 + 50)
Part 4: Solving for a Variable
- x = 22 or x = -22
- x = 5 or x = -5
- No solution. (Absolute value can never be negative.)
- First, subtract 3 from both sides: |x| = 11. So, x = 11 or x = -11
Part 5: Brain Challenge!
Answer: The submarine was farther from sea level at -150 meters.
Explanation: The distance from sea level (0) is found by taking the absolute value. |-150| = 150 meters. |-95| = 95 meters. Since 150 > 95, the submarine was farther from the surface at -150 meters.