Ask "historical harvest speed algorithm"
The quick calculation method invented by Shi Fengshou, a master of quick calculation, has been studied for 10 years, which is a method of calculating directly with the brain, also called quick mental arithmetic, quick mental arithmetic. This method breaks the traditional method of counting from the low position for thousands of years, and summarizes 26 formulas by using the carry rule. Counting from the high position and counting with the help of fingers can speed up the calculation, which can instantly calculate the correct results, help human beings develop their brain power and strengthen their ability to think, analyze, judge and solve problems. It is a great pioneering work of contemporary applied mathematics. This set of calculation method, officially named "Fast Algorithm of Historical Harvest" by the state in 1990, has been incorporated into the mathematics textbook of modern primary schools in China's nine-year compulsory education. UNESCO praised it as a miracle in the history of educational science and should be popularized all over the world. The main characteristics of the stone harvest speed algorithm are: from left to right, the correct answer can be reported directly without calculation tools and programs, and it can be applied to mathematical operations such as addition, subtraction, multiplication, division, square root, trigonometric function and logarithm of multi-bit data. The algorithm of historical harvest speed is easy to learn and use. The algorithm is based on high digits, and 26 formulas summarized by the professor of memory history (these formulas are scientific and interrelated without memory) are used to express the law of multiplying one digit by multiple digits. By mastering these formulas and some specific rules, we can quickly perform operations such as addition, subtraction, multiplication, division, power, root, fraction, function and logarithm. Taking multiplication as an example, this paper shows that zero-speed algorithm, like traditional multiplication, needs to deal with each bit of multiplier bit by bit. We call the number being processed in the multiplicand "standard" and the number from the first digit to the last digit on the right side of the standard "last digit". After the standard is multiplied, only the single digit of the product is taken as "this bit", and the number to be carried after the standard is multiplied by the multiplier is "the last bit". ○ Every bit of the product is a single digit of the sum of "Ben plus Backward", that is, the single digit of the sum of-□ standard product = (Ben plus Backward) ○ Then when we calculate, we must find out Ben and Backward one by one from left to right, and then add them to get its single digits. Now, let's give a correct example to illustrate the thinking activity in calculus. (Example) The first digit of the multiplicand is supplemented by 0, and the formula is as follows: 0847536×2= 1695072. The carry rule of the multiplier of 2 is "2 is full of 5 1", 0× 2 is a 0, the last digit is 8, and the last digit is 1, 1 8×2 is a 6. Eight decimals of 1 get 9 7× 2, and the last digit is 5. Four decimals of 1 with 5 decimal digits and 1 get 5 5× 2, and the last digit is 3, and 0 33× 2, and the last digit is 6 with 5 decimal digits/kloc-. Based on these carry rules, the "historical harvest speed algorithm" is gradually developed. As long as it is skillfully used, the purpose of fast and accurate calculation of four-digit addition, subtraction, multiplication and division can be achieved.