Chapter 1, Lesson 2
Vera is an elevator-repair technician. To test the repair she has done today in an office building, she does some trial runs. During the first trial, she starts the elevator at the lobby floor and takes it up 5 floors, down 2 floors, up 9 floors, down 5 floors, down 2 floors. Write and evaluate a numerical expression containing absolute values to find the total number of floors that were involved in this trial run.