速算练习

Mental Calculation Practice: This section collects commonly used mental calculation techniques and generates corresponding problems for students to practice. Students can also refer to the help documentation to understand the mental calculation process. For example: Multiplying numbers in the teens: Multiply the digits of the first digit, add the digits of the last digit, multiply the digits of the last digit. If the digits are the same and the digits of the last digits are complementary (the sum of the last digits equals 10): Multiply one digit by 1, then multiply the digits of the first digit, then multiply the digits of the last digit. If the first multiplier is complementary and the other multiplier has the same digit: Multiply one digit by 1, then multiply the digits of the first digit, then multiply the digits of the last digit. If the digits of the first digits are complementary (the sum of the digits of the first digit equals 10) and the digits of the last digits are the same: Multiply the two digits of the first digit, add the last digit to the product, and use the result as the first part of the product. Multiply the two digits of the last digit (i.e., square the last digits), and use the result as the second part of the product. If there is no tens digit, add a 0. Mental Calculation Practice: 1. Select the practice type. 2. Enter the practice, input the answer, or view the mental calculation process and help documentation. 3. Supports comprehensive practice. 4. Supports batch generation of practice problems and copying them to the clipboard. 5. Support my practice history