Real Numbers

Real numbers are simply the combination of rational and irrational numbers, in the number system. In general, all the arithmetic operations can be performed on these numbers and they can be represented in the number line, also. At the same time, the imaginary numbers are the un-real numbers, which cannot be expressed in the number line and is commonly used to represent a complex number. The concepts related to real numerals are explained here in detail, along with examples and practice questions. The key concept in the number system is included in this article.

Examples

23

-12

6.99

5/2

π(3.14)

Real Numbers Definition

Real numbers can be defined as the union of both the rational and irrational numbers. They can be both positive or negative and are denoted by the symbol “R”. All the natural numbers, decimals and fractions come under this category. See the figure, given below, which shows the classification of real numerals.

Set of Real Numbers

The set of real numbers consist of different categories, such as natural and whole numbers, integers, rational and irrational numbers. In the table given below, all these numbers are defined with examples.

Category

Definition

Example

Natural Numbers

Contain all counting numbers which start from 1.

N = {1,2,3,4,……}

All numbers such as 1, 2, 3, 4,5,6,…..…

Whole Numbers

Collection of zero and natural number.

W = {0,1,2,3,…..}

All numbers including 0 such as 0, 1, 2, 3, 4,5,6,…..…

Integers

The collective result of whole numbers and negative of all natural numbers.

Includes: -infinity (-∞),……..-4, -3, -2, -1, 0, 1, 2, 3, 4, ……+infinity (+∞)

Rational Numbers

Numbers that can be written in the form of p/q, where q≠0.

Examples of rational numbers are ½, 5/4 and 12/6 etc.

Irrational Numbers

All the numbers which are not rational and cannot be written in the form of p/q.

Irrational numbers are non-terminating and non-repeating in nature like √2

Real Numbers Chart

The chart for the set of real numerals including all the types are given below: