How did abacus evolve?

The abacus has a long history and is a great invention of China. So how did the abacus come from? The evolution of abacus is divided into four steps:

1. The earliest people counted with stones, and a stone stands for 1.

2. Later, count them one by one. One chip stands for 1 vertically and 5 horizontally.

3. Put beads in the future. The blue beads above represent 5, and the yellow beads below represent 1. When counting, take the upper beads and the lower beads to the middle grid.

4. Slowly increase to count with an abacus.

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Origin of Sudoku: Sudoku (すぅどく in Japanese and Sudoku in English) The word Sudoku comes from Japanese and means "single number" or "number that only appears once". Simply put, it is a numbers game. It can also be understood that each number is unique in a row, a column or a nine-square grid.

But this concept was originally not from Japan, but from Latin squares, which was invented by Swiss mathematician Euler in the18th century. Born in 1707, Euler is considered as one of the greatest mathematicians of all time.

Euler was a mathematical genius since childhood. I studied ancient Hebrew in the theological seminary in college, but I won the grand prize of the Paris Academy of Sciences for 13 times in a row.

1783, Euler invented a "Latin Rubik's Cube", which he called a "new Rubik's Cube". This is the embryonic form of Sudoku. However, Euler's invention was not taken seriously at that time. It was not until the 1970s that American magazines relaunched it in the name of "digital puzzle".

1984, Shinhiko Jinyuan, an employee of Japanese puzzle magazine Nikoli, stumbled upon this game in an American magazine, thinking that it could be used to attract Japanese readers, so he improved it, made it more difficult, and gave it a new name called Sudoku. As a result, it became an instant hit and made publishers make a fortune. So far, the publishing house has published 2 1 books on Sudoku, some of which were out of stock soon after listing.

The rapid popularity of Sudoku is mainly attributed to a retired judge named Wayne Gould. Gould now lives in Ireland. 1997. He stumbled across the game and wrote a computer program to automatically generate a complete Sudoku box. At the end of 2004, The Times of London opened a column on Sudoku at Gould's suggestion, and then the Daily Telegraph published Sudoku in June 2005.

Later, dozens of daily newspapers around the world set up columns to introduce Sudoku, and some even put them on the front page to attract readers. Magazines and books devoted to this kind of entertainment have sprung up like mushrooms after rain, and related competitions, websites and blogs have also emerged one after another.

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