If it is a multiple of 3, the first block is replaced by A, the second block is replaced by B, and the third block is replaced by C.. For the first time, put the front of A and B (usually put 2 pieces in each pot). Put the reverse of A, the reverse of C, the reverse of B and the reverse of C for the second time. If it is six times, do it twice, and so on, that is, three times. If it's an even number, two pieces are positive the first time and two pieces are negative the second time.

related introduction:

mathematics (Chinese pinyin: shù xué；; Greek: μ α θ η μ α τ κ; English: Mathematics or Maths) is derived from the ancient Greek word μθημα(máthēma), which means learning, learning and science.

Ancient Greek scholars regarded it as the starting point of philosophy and "the foundation of learning". In addition, there is a narrow and technical meaning-"mathematical research". Even in its etymology, its adjective meaning related to learning will be used to refer to mathematics.

its plural form in English and its plural form in French +es as mathématiques can be traced back to the Latin neutral plural (Mathematica), which was translated by Cicero from the Greek plural τ α α θ ι α τ κ? （ta mathēmatiká）。

In ancient China, mathematics was called arithmetic, also known as arithmetics, and it was finally changed to mathematics. Arithmetic in ancient China was one of the six arts (called "number" in the six arts).

Mathematics originated from the early production activities of human beings. The Babylonians in Cuba have accumulated certain mathematical knowledge since ancient times and can apply practical problems. From mathematics itself, their mathematical knowledge is only obtained through observation and experience, and there is no comprehensive conclusion and proof. However, we should fully affirm their contribution to mathematics.