Decimal method is a calculation method, that is, when the unit is not reduced enough, subtract 10 by subtraction and add the remainder to the number in the unit, that is, decimal method. Because the first-grade primary school students are familiar with the addition and subtraction within 10, they use the method of breaking ten to calculate.

For example, for the problem of 13-6, we first divide 13 into 3 and 10, then subtract 6 from 10, and add the 4 of 10-6 to the previous 3 (). Now we advocate addition and subtraction.

Break ten laws and decide: ten MINUS nine, several plus one; Ten MINUS seven, a few plus three; A dozen MINUS five, a few plus five; One dozen MINUS three, several plus seven; A dozen MINUS eight, a few plus two; A dozen MINUS six, a few plus four; A dozen MINUS four, a few plus six; A dozen MINUS two, a few plus eight.

Mathematics (Mathematics or maths, from the Greek word "Má thē ma"; Often abbreviated as "mathematics"), it is a discipline that studies concepts such as quantity, structure, change, space and information, and belongs to a formal science from a certain point of view. Mathematicians and philosophers have a series of views on the exact scope and definition of mathematics.

In the development of human history and social life, mathematics also plays an irreplaceable role, and it is also an indispensable basic tool for studying and studying modern science and technology.

References:

Baidu encyclopedia-mathematics