the problem of mathematics folding in Beijing Normal University Edition < br > The folding operation is actually to fold a part of a graph along a straight line 180, so that it overlaps or does not overlap with another graph on the same side of this straight line, in which "folding" is a process, through which students' spatial imagination ability is exercised, and "folding _ is the result." But empty imagination is absolutely the foundation. Many origami games we played as children actually exercised our imagination. In recent years, there have been many graphic folding problems in the senior high school entrance examination questions in various places. Folding questions have various forms and are flexible, ranging from practical operation questions that examine students' spatial imagination and hands-on operation ability, to theoretical calculation questions that directly use folding-related properties, to comprehensive questions based on folding operation, and even the finale questions. This kind of question can examine students' hands-on operation and spatial imagination, and also comprehensively examine students' ability to analyze and solve problems, which has gradually become a hot spot in the senior high school entrance examination. Br Beijing Normal University Press is the core enterprise of Beijing Normal University Publishing Group, which was established in 1980. It is a comprehensive publishing house with educational publishing as the main body and professional publishing and mass publishing as the two wings. For more than 30 years, Beijing Normal University Press has always adhered to the publishing concepts of "spreading scientific truth, promoting educational innovation" and "promoting Chinese culture and enjoying world civilization", publishing more than/kloc-0.0000 kinds of books, with a circulation of 654.38+0.5 billion copies, and exporting nearly 1,000 kinds of books. More than/kloc-0.00 kinds of books have won national, provincial and ministerial awards.