I was tutoring a student for the ACT Math. He told me there were revisions around late 2015 and he did not want to use real tests or prep material from before that. I suggested using Dr. Jang’s ACT 36 Math Workbook, as it has just come out and I think highly of his other books.
Does anyone know about the nature of the changes that were made (other than the essay, which is obvious). Are there materials describing the changes or prep books that take them into account. How important are the changes and how big a problem is it to use old materials?