There is a "one-stroke" puzzle, with nine points in three rows, and three points in each row form a square. Four straight lines are required to connect these nine points. At first, I walked around the box surrounded by nine points and found that at least five straight lines were needed to connect them. As a result, to find the answer, my mind must break through the box surrounded by these nine points in thinking.
The second step of the game is to connect the same nine points with only three straight lines. At this time, almost everyone will be confused: this is impossible. In fact, the answer is very simple, and it can be connected with a "Z" word line. However, I am afraid that children who have never studied mathematics will find this answer as soon as possible.
Because as adults, unconsciously, we have been framed by other "frames". There is a basic axiom in mathematics: two parallel lines will never intersect. But relativity tells us that two parallel lines will intersect at infinity when they extend indefinitely. In fact, any point in reality will have a size. To break through this restriction, as long as the "Z" three-segment line is extended indefinitely, it is possible to connect at nine o'clock.
The third step of the game only needs a straight line to connect these nine points. I believe that we can easily find the answer at this point, because as long as we break through the mathematical "line is not thick" box again, we can include all nine points with a very thick line.