There are some differences in textbooks between Japan and the United States; the most fundamental difference we assume is that, in Japan, textbooks are owned by each student, instead of being leased to students as American textbooks. Students are allowed to write notes and to draw a line under important points or difficult points on the textbook pages during classes. Therefore, students can make use of what they have written in textbooks during review of lessons at home. The teachers recommend students such learning methods.