Real number is a general term for rational number and irrational number. Real and imaginary numbers * * * together form a complex number. Real numbers can be divided into rational and irrational numbers, or algebraic and transcendental numbers. Real number sets are usually represented by the black letter r, and real numbers are uncountable.
Real number is the core research object of real number theory. The set of all real numbers can be called real number system or real number continuum. Any complete Archimedean ordered field can be called a real number system. It is unique in the sense of order-preserving isomorphism and is usually represented by R.
Because R is an arithmetic system that defines arithmetic operations, it is called the real number system. Real numbers can be used to measure continuous quantities. Theoretically, any real number can be expressed as an infinite decimal, and to the right of the decimal point is an infinite series (cyclic or acyclic).
In practice, real numbers are often approximate to a finite decimal (n digits are reserved after the decimal point, and n is a positive integer). In the computer field, because computers can only store a limited number of decimal places, real numbers are often represented by floating-point numbers.
The importance of learning mathematics;
1. Mathematics is the foundation of modern science and plays a key role in promoting the development of physics, engineering, economics, biology and many other disciplines. The development of these disciplines has further promoted the progress of science and technology and the development of society.
2. Mathematics is an important tool to exercise logical thinking and abstract thinking. Learning mathematics helps to cultivate people's logical thinking ability and abstract thinking ability, so that people can better understand and analyze problems and improve their ability to solve problems.
3. Mathematics is also widely used in daily life. From shopping to financial investment, from work to life and entertainment, you need to use mathematical knowledge. Mastering math skills is helpful to improve people's quality of life and work efficiency.