The present study examines the effectiveness of incorporating worked examples with prompts for self-explanation into a middle school math textbook. Algebra 1 students (N = 75) completed an equation-solving unit with textbooks either containing the original practice problems or in which a portion of those problems were converted into a combination of correct, incorrect, and incomplete examples. Students completed pre- and posttest measures of algebraic feature knowledge, equation-solving skills, and error anticipation. Example-based textbook assignments increased students' equation-solving skills and their ability to anticipate errors one might make when solving problems. Differences in students' anticipation of various types of errors are also examined. Error anticipation, a particular form of "negative knowledge," is a potentially important skill that relates to algebraic feature knowledge and equation-solving skills.