A number is composed of one or more digits arranged in a specific order. We must deal with numbers and number system in many circumstances throughout our daily lives. To count, we use natural numbers. When researchers encountered the concept of cardinality, they came up with the number 0, to represent the cardinality of an empty set. To find the total number of objects in a given set, we started using whole numbers.
As the field of research developed, mathematicians started discovering equations like x + 2 = 0. They needed a number that satisfies the equation to solve for x. As , x= -2 was the number that satisfies the equation.This led to the introduction of negative numerals. The number line is the most common application for negative numbers, which led to the discovery of coordinate axes in geometry.
The concept of real numbers helps us to write the numbers between 0 and 1. But, the knowledge of real numbers was not sufficient to solve equations like x2 + 1 = 0, where x will be -1. This led to the origin of complex numbers.
Hence as the saying goes “Necessity is the mother of invention,” so were the classification of mathematical numbers into different systems took birth.
The classification of numbers is very important because each form of number has a distinct use. Numbers can be classified as given below:
- Natural numbers
- Whole numbers
- Integers
- Fractions
- Decimals
- Rational numbers
- Irrational numbers
- Real numbers
- Complex numbers
Each set of numbers has its own significance and they are interlinked. The pictorial representation below provides a visual picture of the number system.

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