Number System- Part 2 of 5

Number System (Part 2 of 5)

Types of Numbers

This topic covers explanation of all types of numbers that you come across in Mathematics

Natural numbers
The counting numbers {1, 2, 3, ...}, are called natural numbers. They include all the counting numbers i.e. from 1 to infinity.
Ex. 1,2,3….and so on

Whole numbers
They are the natural numbers including zero. Not all whole numbers are natural numbers, but all natural numbers are whole numbers.
Ex. 0,1,2,3…and so on

Integers
Positive and negative counting numbers, as well as zero.
Ex.  and so on…-2,-1,0,1,2… and so on

Rational numbers
Numbers that can be expressed as a fraction of an integer and a non-zero integer.
Ex. a/b , 5/7 , 2/9 …

Real numbers
All numbers that can be expressed as the limit of a sequence of rational numbers. Every real number corresponds to a point on the number line.

Irrational numbers
A real number that is not rational is called irrational.
Ex. 

Even and odd numbers
A number is even if it is a multiple of two, and is odd otherwise.
Even no. 2, 4, 6, 8….and so on
Odd no. 1, 3, 5, 7…and so on

Prime number
A number with exactly two positive divisors.
Ex. 13, 17, 19…

Composite number
A number that can be factored into a product of smaller integers. Every integer greater than one is either prime or composite.
Ex. 14, 15, 16…