Aaargh! You used the question bank from your Pre-Algebra textbook. Problem #3 for one student is 8(-3) and for another student is -5(-4). Obviously, those are not assessing the same concept! This question bank will assure consistency and parallel structure across multiple versions of a quiz or test while properly randomizing the values.
The 33 problems cover a full range of simple integer expressions with combinations of negative and positive values. Several problems ask for determination of positive or negative results without evaluating expressions. 13 problems are numerical expressions, and seven are "evaluate when a = . . ."
This will be part of my "Pre-Algebra Chapter 1 Question Banks" collection. It is created in ExamView 7.5 and is useful if you wish to dissect some problems and hone your skills at writing dynamic questions.