How to calculate mental arithmetic and what is mental arithmetic?

Through the process of perception, image, memory, etc., the abacus operation is completed in the brain, that is, abacus mental arithmetic.

Abacus, is to abacus as a tool, addition, subtraction, multiplication, division, square and other operations of the calculation method, its use of skills have a certain rules and formulas, when the user can skillfully operate the abacus, in addition to quickly find the correct answer, but also through the growth of brain cells, the abacus of the disc type, grade and abacus floating changes depicted into the brain, this kind of live abacus image, called "virtual disk".

It uses perception, image, memory and other processes to complete abacus in the brain, which is what we call abacus mental arithmetic.

Abacus-style mental arithmetic, its speed is very amazing. Often, as long as you hear the number of questions or see the type of calculation question yourself, the calculator can blurt out the answer or write it out immediately. Therefore, abacus mental arithmetic is an advanced computing technique.

Learn what mental arithmetic is.

Use the brain to complete the calculation of the disc type, grade and fluctuation change of the abacus.

In the process of teaching mental arithmetic, abacus is the foundation, and through the operation of real abacus (abacus), learners can understand the changes and methods of the four calculations. With the proficiency of skills, the image in the learner's brain is gradually established, and the function of mental arithmetic is generated through the imitation of the image to destroy the real operation (virtual disk), so the Xinzhou Bishu is the advanced manifestation of the abacus. Abacus and mental arithmetic are like human feet, and you can't choose one alone.

In the study of abacus, students can master their numeracy skills and memory skills. The appearance of memory ability is the most important abacus image in the mental arithmetic process, and in the process of calculation, the abacus image is continuously transformed from a static bead into many moving beads in an instant, and it is completed in a very short time. Therefore, the more proficient the abacus skills, the more superb the mental arithmetic will be.

Therefore, in the process of learning mental arithmetic, abacus and mental arithmetic should go hand in hand, with abacus laying the foundation first and mental arithmetic being expressed in the second moment. When the difficulty of abacus increases, the progress will be slow, but mental arithmetic can be more unhindered and imaginative.

Algorithm formula: The formula is unique to the abacus Institute It was first seen in Wu Jing's "Nine Chapters of Algorithm Analogy" (1450). The "ninety-nine" formula used in multiplication originated very early and was used in calculations during the Spring and Autumn Period and the Warring States Period.

Shen Kuo, a scientist in the Northern Song Dynasty, introduced the "method of addition" in volume 18 of his "Mengxi Writings": "Only the method of increasing into one is slightly different, and its technique does not need to be multiplied and divided, but it is only profitable to make up for losses."

If you want to divide by nine, increase by one, and divide by eight, increase by two, but one person is one cause." "Nine divides by one" later became "nine plus one", "eight divides by two" and later became "eight by two" and other mantras. It can be seen that the "addition method" is the predecessor of the "reduction and division method".

Yang Hui recounted the "Nine Returns" in "Multiplication and Division" and added 32 new formulas to the four "ancient brackets" that were circulating at that time, which were close to today's formulas. Zhu Shijie's Enlightenment of Arithmetic (1299 volumes) of the Yuan Dynasty contains 36 sentences of the Nine Gui formulas, which are roughly the same as those commonly used today.

In the 14th century, Ding wrote eight volumes of algorithms (1355) with a "recipe for colliding with returns". In short, the entire attribution formula was completed in the Yuan Dynasty. With the four formulas, the abacus algorithm formed a system that has been used for a long time.

Since the Ming Dynasty, the Chinese abacus has been extremely popular, and has spread to Japan, Korea, Southeast Asian countries, and then became popular in the Americas. Because the abacus is not only a very simple calculation tool, but also has a unique educational function, it is still popular.