This is a set of three books from Keirinkan's i-Work for Junior High School 1st Grade Mathematics: i-Work, i-Work Plus, and the Answer/Explanation Collection. [Product Contents] * i-Work Junior High School 1st Grade Mathematics * i-Work Plus Junior High School 1st Grade Mathematics * Junior High School 1st Grade Mathematics Test Answer/Explanation Collection [Condition of the Product] There are some minor scratches and stains from use, but there are no markings, and the books are generally in good condition. [Other] These books can be used for self-study or as materials for cram schools. Thank you.