I. Arabic numerals

Arabic numerals were invented by ancient Indians and later spread to Arabia and Europe. Europeans mistakenly thought it was invented by Arabs, so they called it "Arabic numerals". Because it has been circulated for many years, people call it Yi, so people still mistakenly believe that these numerical symbols invented by ancient Indians are called Arabic numerals.

Second, 99 songs

Jiujiuge is the multiplication formula we use now. As early as the Spring and Autumn Period and the Warring States Period BC, Jiujiu songs have been widely used by people. In many works at that time, there were records about Jiujiu songs. The original 99 songs started from "99.8 1" to "22.24", with 36 sentences. Because it started with "998 1", it was named 99 Song.

The expansion of Jiujiu Song to "One for One" was between the 5th century and10th century. It was in the 13 and 14 centuries that the order of Jiujiu songs became the same as it is now, from "one for one" to "9981". At present, there are two kinds of multiplication formulas used in China. One is a 45-sentence formula, usually called "Xiao Jiujiu"; There is also a sentence 8 1, which is usually called "Big Uncle Nine".

Third, Mobius ring

Mobius ring is a topological structure with only one face and one boundary. You can twist a piece of paper into 180 degrees, and then stick the two ends together to form a Mobius ring.

Cutting Mobius ring along the midline can get a larger ring for the first time. The second time and after, you will get two nested rings every time. The middle will never break, which is also the magic of Mobius ring.

Mathematical celebrities:

Rene Descartes

Rene descartes, 1596 was born in Dulan, France on March 3 1. Descartes was a great philosopher, physicist, mathematician and physiologist. The founder of analytic geometry. Descartes was one of the founders of modern European bourgeois philosophy, and Hegel called him "the father of modern philosophy". He is self-contained, integrating materialism and idealism, and has far-reaching influence in the history of philosophy. At the same time, he is a scientist who dares to explore, and his analytic geometry is of epoch-making significance in the history of mathematics. Descartes is one of the most influential masters in the field of philosophy and science in Europe in the17th century, and is known as "the ancestor of modern science".

Euclid

Euclid (Greek: ε υ κ λ ε ι δ η? , about 330 BC-275 BC, Alexandria), an ancient Greek mathematician, was called "the father of geometry". During the period of Ptolemy I Soter (323 BC-283 BC), he was active in Alexandria. His most famous book, The Elements of Geometry, is the foundation of European mathematics. It puts forward five postulates and develops Euclidean geometry. It is widely regarded as the most successful textbook in history. Euclid also wrote some works about perspective, conic curve, spherical geometry and number theory, and was the founder of geometry.

Archimedes

Archimedes (287 BC-2 BC12) was an ancient Greek philosopher, mathematician and physicist. Born in Syracuse, Sicily. Archimedes has been to Alexandria. It is said that he invented Archimedes screw pump when he lived in Alexandria. Later, Archimedes became a great scholar who was both a mathematician and a mechanic, enjoying the reputation of "the father of mechanics". There are more than 10 mathematical works handed down by Archimedes, most of which are Greek manuscripts. Archimedes once said: Give me a fulcrum and I can move the earth. This sentence tells us: we must have the courage to find this fulcrum and the courage to find the truth.