This is a set of two problem books designed to help second graders overcome common stumbling blocks. I purchased these new and used them by making copies. While there are some page-opening marks from copying, there is no writing inside. The answer keys have not been removed. ★Please understand that these are used items that have been handled by someone else before purchasing. ――――― 【Product Details】 Textbooks to conquer the walls of arithmetic, both here and there. Smoothly conquer the walls of arithmetic. - Title: Second Grade: Time and Hours - Title: Second Grade: Length and Volume (Units) - ISBN: 978-4-7746-5772-3 - ISBN: 978-4-7746-5773-0 - Certificate of Mastery: Second Grade: Conquered Time and Hours - Certificate of Mastery: Second Grade: Conquered Length and Volume Thank you for looking. ---- I am also selling many other study guides, problem books, and English教材. #Floren's Study Guides & Problem Books Please feel free to take a look at my other study materials & English教材 as well. KUMON, high level, arithmetic, volume, length, units, time, time, time, smoothly conquer the walls of arithmetic, KUMON