由数位调换和数值估计等构成的问题,常称为数字问题。有些数字问题的解答初看起来垂手可得,但有时却化了九牛二虎之力仍不易得手。用什么方法来算好呢?数学家波利亚指出:“为了取得真正的成就……必须学习合情推理(猜想)”。它能帮助我们比较迅速地发现事物的规律,并能提供我们研究的线索和方向,具有启示和指导作用。 The problem posed by digital transposition and numerical estimation is often called the digital problem. At first glance, some of the answers to the numerical questions are not readily available, but at times they have not turned a favor. What method is used to calculate it? Mathematician Poliya pointed out: “In order to achieve real success ... we must learn co-rationality (conjecture)”. It can help us discover the law of things relatively quickly, and can provide the clues and directions of our research, which has enlightenment and guidance.