In fact, I don't think that people who create their own arrays can be much worse at mathematics, such as Bagua Array, Sky Absolute Array, Fierce Array, Bloody Array, Red Water Array, Yuanyang Array and so on. Such a person must be super good at math. After all, we all rely on formulas to calculate now, and ancient people can make arrays with their heads at will, which is also shocking. It is said that Han Xin is a master of mathematics, which comes from the folklore "Han Xin ordered soldiers".
Liu bang asked him how many soldiers he could take. Han Xin said the more the better, and Liu Bang said, Now tell me how long there are soldiers in the barracks. Han Xin made a battalion of soldiers form a four-way column, with two more people at the end of the column, then a five-way column with one more person at the end, then a seven-way column with two people at the end and three people at the end. Han Xin immediately told Liu Bang that the number of soldiers in this battalion was 1906.
If Liu Bang didn't believe it, he ordered people to read it. Yes 1906 people. In order to prove his vision, Liu Bang invited some soldiers to let Han Xin count off. Han Xin ordered three people to stand in a row. After standing well, the captain reported that there were two more people at the end of the team, and Han Xin ordered every five people to stand in a row. The captain came to report that there were three more people at the end of the team and ordered seven people to stand in a row. The captain came to report that there were two more people at the end of the team. In fact, this is a bit ridiculous, but the real source is in the calculation of Sun Tzu's Art of War, because there are many sayings, such as: Han Xin took 1500 soldiers to fight, four or five hundred people died, three people stood in a row, and two more people; Stand in a row of five people, four more; Seven people stand in a row, plus six people. Han Xin quickly gave the number: 1049.
In Sun Tzu's calculation, there is such an arithmetic problem: "Today's events are unknown, and three or three leaves two, five or five leaves three, and seven or seven leaves two. What is the geometry of things? " According to today's words: divide a number by 3 and 2, by 5 and 3, by 7 and 2, and find this number. So it was quoted in the allusion of "Han Xin ordered soldiers".