NUMBER SYSTEM IN CHENNAI

KCS EDUCATION, delivers quantitative aptitude course. Series of articles on various topics of quantitative aptitude are presented here. Firstly, we will discuss number system. Numbers: Ten digits in Hindu-Arabic System: 0,1,2,3,4,5,6,7,8,9 Numeral: A number is denoted by a group of digits called numeral a) Face Value: The face value of a digit in a numeral is its own value Example: 1357 Face value of 1 is 1 Face value of 3 is 3 Face value of 5 is 5 Face value of 7 is 7 b) Place Value: • Place value of unit digit = unit digit x 1 • Place value of tens digit = tens digit x 10 • Place value of Hundreds digit = hundreds digit x 100 Types of Numbers: (i) Natural Numbers: 1, 2, 3, 4, 5, 6, 7……. (ii) Whole Numbers: 0, 1, 2, 3, 4, 5, 6, 7, 8… (iii) Integers: … -3, -2, -1, 0, 1, 2, 3, 4….. • Positive Integers = {1, 2, 3, 4, 5, 6…..} • Negative Integers = {-1, -2, -3, -4…} • Non-Negative Integers = {0, 1, 2, 3, 4, 5, 6…..} (iv) Even Numbers: Divisible by 2 • 0, 2, 4, 6, 8, 10, 12… (v) Odd Numbers: Not divisible by 2 • 1,3,5,7,9,11… (vi) Prime Number: Natural numbers with exactly two factors namely itself and one • Prime Numbers less than 100 are 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97