There are many theories about this. According to the Book of Changes, 1 is the largest, because 1 is the initial, and Buddhists say that 9 is the largest and most auspicious, and the meaning of 9 is permanent. Guangdong people say that 8 is the best, 8 represents the best ternary geomantic omen, and 4 represents Wenchang, which is beneficial to reading and paperwork. In the mysterious geomantic omen, 6 stands for Wu Quxing, which is conducive to the marriage of military writers and ordinary people. Numbers themselves are not good or bad. What matters is where they are used. For example, if you take your lucky number, it may be any of these numbers according to your birth time. If you want to study hard, then we will try to let you have digital items with 4 to help you study. If you are a worker or gendarmerie, we will help you with 6, and so on. What suits you is the best.