A, split number method:
Divide a number into several numbers to add and subtract, thus making the calculation simple. For example, when calculating 100+20+30, you can add 20 and 30 to get 50, and then add it to 100, so the whole calculation becomes 100+50, which is simpler to calculate.
Second, add up to ten:
Divide a number into several numbers to add and subtract, so that the sum or difference of one or several numbers is a multiple of 10 or 10, thus making the calculation simple. For example, when calculating 8+6, you can divide 8 by 2 and 6, add 2 and 6 to get 8, and add 6, then the whole calculation becomes 8+2+6= 16.
Third, the formula method:
Remember some common calculation results in the form of formulas, such as "222 is like 4, 3 is 3 plus 9", so these results can be directly used for calculation.
Fourth, the transformation method:
Some uncommon calculation problems are transformed into common calculation problems, thus making the calculation simple. For example, when calculating 1/3+2/3, two fractions can be converted into the addition of two integers, that is, 1 and 2 are added to get 3, and then the common denominator of 1/3 and 2/3 is subtracted to get 1.
Five, direct division:
When comparing or calculating complicated fractions, the first place (the first place or the first two places) of the quotient is obtained by "direct division", so as to get the correct answer. For example, when comparing 3.2 and 3.5, we can directly divide them to get 1 and 2, so 3.2 is less than 3.5.
Classification of fast calculation
A, Jinhua whole brain fast calculation:
The operation principle of Jinhua whole brain quick calculation is to stimulate the brain through the activities of both hands, so that the brain can directly produce sensitive conditioned reflex to numbers, so the purpose of quick calculation can be achieved. Take the hand as the operator, and produce an intuitive operation process. The brain acts as a process of memory, quick response and expression.
Second, the rapid calculation of historical harvest:
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.
Third, Wei Wude's quick calculation:
Wei's quick calculation allows learners to master the quick calculation method of addition, subtraction, multiplication and division of any number quickly and accurately in a short time with an idea and a method without any calculation tools. So as to quickly improve learners' quick calculation ability in oral and mental arithmetic.
Fourth, swallow gold into the sleeve:
Fast algorithm is a numerical calculation method invented by ancient businessmen in China. Ancient people's clothes were all sleeves, and when calculating, they only saw hands in the sleeves. This is called swallowing gold quickly.