Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Filled with errors.

My son bought this book to prepare for the Math II subject test. The book covered all of the SAT's topics, but the practice sections were horrible. There were errors everywhere. Most of them involved simple algebra, but many were typos. The book would make mistakes like 1+3=2. In many situations the answer key would contradict the answer explanations. On the plus side, the full-length practice tests did not have too many errors, and they gave an pretty accurate prediction of my son's score on the SAT Math II.