Being able to make pottery using a potter's wheel means understanding the principle of rotation.
In mathematics, a solid of revolution is a three-dimensional figure that rotates once around a straight line as an axis.
For example, a column or cone that can be seen when a rectangular or right triangle-shaped piece of paper is attached to a wooden chopstick and turned is a solid of revolution.
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15 Representative tools of the prehistoric era: the golden ratio and the sphere of revolution

For our ancestors, 3 was the first number to which the word 'all' could be attached, and it was a number that represented the whole because it included the beginning, middle, and end.
The power of three is universal and represents the tripartite nature of the world, consisting of sky, earth, and sea.
3 is the human body.
soul .
It represents spirit, birth, life, and death, beginning, middle, and end, past, present, and future, and the three phases of the moon (crescent, half, and full moon).
Also, the basis of 3 is heaven, earth and man, and yesterday (past), today (present) and tomorrow (future).
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31 The Founding of Gojoseon and the Dangun Myth: Among the Numbers 3

The Hwangjonggwan, which Park Yeon created to obtain Hwangjongum, also influenced weights and measures.
In pre-modern societies, the length of one cheok varied slightly from era to era and region to region.
Sejong felt the need to reorganize the weights and measures system as it became disorganized.
So, based on the Hwangjonggwan created by Park Yeon, Hwangjongcheok was established.
The Hwangjong-gwan is 9 chi plus 1 chi to make 1 chi (尺, ja), and is called Hwangjong-cheok.
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85 Ancient Music and Instruments: From the Three-Part Profit and Loss Method

A broken, round artifact, such as the 'Smile of Silla', can be restored to its round shape by using the circumcenter of a triangle.
To restore a broken triangle using mathematics, you must understand how to construct a perpendicular bisector and the circumcenter of a triangle.
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97 Silla relics from Gyeongju Wolji: 14-sided tombstone and restoration of relics

A major characteristic of the Goryeo founding myth is that it sanctifies royal authority through the medieval science of feng shui.
Feng Shui considers the universe, nature, various human-made structures, and human life within this environment as a single organism.
The life principles of these organisms maintain a strict orderly system, and because they are repeatedly applied in the same way in both the macro and micro worlds, the principle is expressed in a complex numerical system, which is the essence of Feng Shui.
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103 Feng Shui in the Goryeo founding myth: Among the five elements of yin and yang and various formations

There is something else that is mathematically most surprising in the Haeinsa Tripitaka Koreana.
Among the 52,396,888 characters in the Tripitaka Koreana, there are only 158 typos, which is an astonishing result that the probability of typos is only (%).
Even though numerous people worked on it, there are almost no errors, and the level of handwriting and engraving is astonishing, as if it were created by a single person.

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141 Haeinsa Tripitaka Koreana woodblocks made during the Mongol invasion: 50 million characters and probability calculations
Sejong not only studied mathematics by solving problems himself, but also encouraged officials, including the nobility, to study science and engineering.
It is said that when the Gyeongsang-do governor donated 100 volumes of the mathematics book “Yang Hui’s Mathematical Methods” published in Song China, they were evenly distributed to the Jiphyeonjeon, the Ministry of Taxation, and the Seopsan-guk (習算局) of the Seoungwan.
In this way, Sejong realized the importance of mathematics as a fundamental discipline, so he studied mathematics himself, encouraged scholars and researchers, and even had scholars conduct research and investigations.
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176 King Sejong, who studied mathematics himself: Joseon's industrial and academic world

《Gusuryak》 contains the origin and fundamentals of numbers, methods of representing fractions and their calculations, the sum of series added using rules, and simultaneous equations.
Also, the shapes of the mountain branches and the method of arranging the mountain branches for addition, subtraction, and multiplication are explained in the 'Numbers' section.
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252 Joseon as reflected in Hamel's Journal: From Choi Seok-jeong's Gusuryak

Kim Jeong-ho devised a number of symbols to facilitate quick and easy recognition of the numerous place names, numbering approximately 11,700, and organized these symbols into a kind of legend called a "map chart" to aid users' understanding.

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278 Kim Jeong-ho's Daedongyeojido, a compilation of Joseon cartography: from the 100-ri scale and scale