1, decimal method, also known as borrowing decimal method, is a calculation method. When the unit is not reduced enough, subtract 10 by subtraction and add the remainder to the number in the unit, that is, the decimal method. It means that it is simple and small to turn the carry addition of numbers less than 20 into the familiar problem of ten plus several for primary school students.
2. The definition of calculation can be used in many aspects, from a fairly precise definition, such as arithmetic with various algorithms, to a more abstract definition, such as the calculation of strategy in a game or the calculation of the success probability of two people's relationship.
3, abdication subtraction within 20, abdication subtraction should be kept in mind, starting from the unit. Don't forget who is the one who doesn't advance or retreat. If the interval is 1, it is best to remember that 0 becomes 10.
4. Arithmetic is the oldest, most basic and initial part of mathematics. It studies the properties and operations of numbers. The oldest mathematical arithmetic is formed by accumulating the properties of numbers and the experience of four operations between numbers in the process of application and sorting them out. All mathematics in ancient times was called arithmetic, and modern algebraic number theory originally developed from arithmetic. Later, the concept of arithmetic mathematics appeared, which replaced the meaning of arithmetic and included all mathematics.