2022 Oin Junior Open Mock Exam (1st), Oin Open Mock Exam (2nd) Original, Oin Junior High Calculation Special Training The mock exams include answer keys and explanations. There is some writing, but I will erase it as much as possible before sending. Please forgive any remaining marks. As a bonus, I will include the Oin Junior High Summer Calculation Special Training. There is writing throughout. There are no answer keys or explanations, but all the answers are written in.