Multiplication: Distribution Law =ac+ab=a(b+c)
Constraint law =abc=a(bc)
Commutation law =ab=ac
Product Invariant Property =ab=(a÷c)×(bc)(c≠0)
Addition: Law of Association =a+b+c=a+(b+c)
Commutation law =a+b=b+a
Division: a÷b÷c=a÷(b×c)(b≠0, c≠0)
Quotient invariant property = a ÷ b = (a× d) ÷ (b× d) (b ≠ 0, d ≠ 0) = (a ÷ d) ÷ (b ≠ 0, d)
Subtraction: a-b-c=a-(b+c)
Fast calculation method
Whole brain fast calculation is a course of fast brain calculation technology developed by simulating computer operation program, which can let children quickly learn to add, subtract, multiply, divide, multiply and look up any number. So as to quickly improve the operation speed and accuracy of children.
The working principle of fast calculation of the whole brain;
Stimulating the brain through the activity of the hand makes the brain directly produce sensitive conditioned reflex to numbers, so as to achieve the purpose of fast calculation.
(1) With the hand as the operator, an intuitive operation process is generated.
(2) As a memory, the brain can react quickly and express the operation process.
Extended data
The purpose of international Olympic competition is to discover and encourage young people with mathematical talent in the world, create conditions for scientific education exchanges among countries, and enhance the friendly relationship between teachers and students in various countries.
This contest (1959) was initiated by Eastern European countries and funded by UNESCO. The first competition was hosted by Romania and held in Bucharest from July 22 to 30. 1959. Bulgaria, Czechoslovakia, Hungary, Poland, Romania and the Soviet Union participated in the competition.
After that, the International Olympic Mathematics Competition was held in July every year (1980 only once), and the participating countries gradually expanded from Eastern Europe to Western Europe, Asia and America, and finally expanded from 1967 to the whole world. In 20 13, more than 80 teams participated in this competition. The United States entered the competition in 1974 and China entered the competition in 1985.
After more than 40 years of development, the operation of the International Mathematical Olympiad has gradually become institutionalized and standardized, and a set of established routines has been followed by previous hosts.
The International Olympic Mathematics Competition is hosted by the participating countries in turn, and the funds are provided by the host country; However, the travel expenses are borne by the participating countries. Participants must be middle school students under the age of 20, with 6 people in each team; Two other mathematicians were appointed as team leaders. The test questions were provided by the participating countries, then selected by the host country and submitted to the examiners' committee for voting, resulting in six test questions.
The host country does not provide test questions. After the test questions are determined, they will be written in English, French, German, Russian and other working languages, and the team leader will translate them into the national language. The examiners' committee is composed of leaders of various countries and the chairman designated by the host country. This chairman is usually the authority on mathematics in this country.
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