Why did ancient China call "mathematics" "arithmetic"?
In ancient mainland china, "arithmetic" referred to a kind of bamboo computing instrument, "arithmetic" refers to the technology of operating this computing instrument, and also refers to all the mathematical knowledge related to calculation at that time.
The term "arithmetic" officially appears in the Nine Chapters of Arithmetic. In the Sui and Tang dynasties, the state established a special institution for the training of astronomers and mathematicians, "Arithmetic", which is equivalent to the mathematics department in the university today, and the teaching books include "Sun Tzu's Algorithm", "Wucao Arithmetic Classic", "Nine Chapters of Arithmetic" and other arithmetic books.
Since the 19th century, some mathematical disciplines in the West, including algebra, trigonometry, analytic geometry, calculus, probability theory, etc., have been introduced to the mainland, Western missionaries mostly use "mathematics", and ancient Chinese arithmetic still uses "arithmetic". In 1935, the Chinese Mathematical Society established the meaning of ~"arithmetic", and arithmetic and mathematics still coexist. It was not until 1939 that Tsinghua University changed the "Department of Arithmetic" to the "Department of Mathematics".