From the meaning of the question, when calculating decimal addition and subtraction, the decimal point of each number should be aligned first, that is, the numbers on the same digit should be aligned, and then the calculation should be carried out according to the law of integer addition and subtraction. So the answer is numbers. When calculating decimal addition and subtraction, you should first align the decimal points of each number, that is, align the numbers on the same digit, and then calculate according to the law of integer addition and subtraction.
Addition and subtraction is one of the most basic operations in mathematics. They are not only the simple combination of addition and subtraction, but also the embodiment of mathematical concepts and ways of thinking. Addition and subtraction is one of the most basic mathematical concepts of human civilization, and its history can be traced back to ancient times.
In ancient times, people used various methods to calculate addition and subtraction, such as stones, ropes, fingers and so on. With the passage of time, mathematicians have gradually developed more abstract and complex mathematical tools and concepts to better understand and solve practical problems.
Addition is a mathematical operation that describes the sum of two or more quantities. The basic properties of addition are interchangeability and combination, that is, a+b=b+a and (a+b)+c=a+(b+c). The symbol of addition is "+",which means that two or more numbers are added. For example, 2+3=5, which means that 2 and 3 add up to get 5.
Application of addition and subtraction
Addition and subtraction are widely used in mathematics, such as algebra, geometry, trigonometric functions and so on. In algebra, addition and subtraction can be used to describe the relationship and change between variables; In geometry, area, perimeter, etc. can be calculated by addition and subtraction.
In trigonometric function, addition and subtraction can be used to describe the relationship and change between angle and length. Addition and subtraction can also be used to solve various practical problems, such as shopping, calculation time, calculation speed and so on. Addition and subtraction is one of the basic operations in mathematics and plays a very important role in mathematics.