##
PEA-305 WORKBOOK:

###
NUMBER SYSTEM

Natural Numbers

The counting numbers are commonly called natural numbers. For example Natural Number, N = {1, 2, 3 …} ● All natural numbers are positive. ● The smallest natural number is 1. ● Zero (0) is not a natural number.

Whole Numbers

All the natural numbers including Zero are called Whole Numbers. It is also known as non-negative integers. For example Whole Numbers, W = {0, 1, 2, 3 …}.

Integers

Whole numbers as well as negative numbers form the set of integers. It can be classified into two types, (i) Positive integers {1, 2, 3…} (ii) Negative integers {– 1, – 2, – 3…} (iii) Zero is neither a positive nor a negative integer.

Even Numbers

All the counting numbers which are divisible by 2 are called even numbers. For example 2, 4, 6, 8, 10…2n ● Unit place of an Even number is 0, 2, 4, 6, or 8.

Odd Numbers

The numbers which are not divisible by 2 are called odd numbers. For Example 1, 3, 5, 7, 9, 11 … (2n-1). ● Unit place of an odd number is 1, 3, 5, 7,or 9. Odd * Odd = Odd Even * Even = Even Odd * Even = Even