1, the same number of decimal places, the sum of single digits is 10. The calculation process can be simplified as two digits multiplied by the same decimal places, and the sum of the decimal places is 10. For example: 23×27, both numbers are less than 30, which can be directly multiplied by ten digits, that is, 2×2=4, and the result of adding single digits is 7+3= 10, and the result is 40.
2. Fast calculation method of dozens of eleven times dozens of eleven: For the multiplication of two numbers of dozens of eleven times dozens of eleven, a special fast calculation method can be adopted. For example, 2 1×4 1 can be transformed into (20+ 1)(40+ 1), and after expansion, 820+20+40+ 1=88 1 is the final result.
3. Fast calculation method of head-tail complementarity: Multiplying two numbers with complementary ten digits and the same single digit can simplify the calculation process. For example: 67×47, the ten digits of the two numbers are 6 and 4 respectively, and the single digit is 7. You can convert two numbers into 60+7 and 40+7 respectively, and then multiply them directly to get the result.
Benefits of using a calculator
1, improve the calculation speed: Calculator can quickly and accurately complete all kinds of mathematical calculations, whether it is simple addition, subtraction, multiplication and division or complex operations such as power and root, it can be easily completed. This has greatly improved people's work efficiency and learning efficiency. Convenient and quick: the calculator is simple to use and easy to operate, and there is no need to memorize complicated operation rules and skills.
2. Reduce errors: The calculator can automatically complete the calculation and display the results, avoiding possible errors and mistakes in manual calculation. This makes people trust their own calculation results more, and reduces the troubles and losses caused by calculation errors. Promote study and work: It can help people complete calculation tasks faster and more accurately, and improve work efficiency and learning effect.
3. Stimulate creativity: The emergence of calculators has also stimulated people's creativity. People can explore new mathematical concepts and algorithms by using calculators and develop smarter, more efficient and more interesting mathematical applications and algorithms. This will help to promote the development of mathematics and computer science and create more value for mankind.