The Constructing and interpreting absolute value exercise used to appear under the Pre-algebra Math Mission. This exercise practices using the absolute value in context and as a distance measurement.
Types of Problems
There are two types of problems in this exercise:
- Select the correct answer: This problem provides a situational problem and asks for information. The answer choice is provided in a multiple choice format on the right side of the screen.
- Enter the correct answer: This problem gives a word problem and this time the student is asked to find the answer and type it in the space provided.
Strategies
Thinking of absolute value as a distance (rather than "turning things positive") can make these problems easier, although it is not necessary.
- The expression means the magnitude of the distance between x and y.
- The answer to the multiple choice type problem is almost always the expression that has the absolute value of a difference. The only exception research has found is where the answer was "is equal to " as opposed to being smaller or greater than this amount.
- If one object is above zero and the other is below zero, the distance between them can be found by adding their magnitudes.
- Decimals and fractions are permitted interchangeably.
- Remember that moving in a negative direction can be represented by a negative number. This is necessary on some of the Enter the correct answer problems.
Real-life Applications
- Absolute value can be used in applications connecting algebra to geometry.
- The absolute value function is an example of a continuous but non-differentiable function (specifically at zero).
- Absolute value extends into the concept of modulus for complex numbers.