Theory at a Glance

Introduction

1. Local Value :
A local value of a number is the face value of that number. For example the local value of 4 in 3248 is 4.
2. Place Value
A place value of a number is the value of the place it occupies times its local value. For example the place of 4 in 3248 is forty.
3. Absolute Value
The absolute value of a number is the number that remains after neglecting the sign of the given number. Absolute value of a number x is denoted by |x|. So, |x|= x if x is positive |x|= - x if x is negative
For example
|35| = 35 and |- 35| = + 35

Number Types in Numerical Aptitude Tests

There are ten types of number generally used in numerical aptitude tests. They are:
1. Even Numbers
All numbers which can be divided by 2 are called even numbers.
For example 2, 4, 6, 8… are even numbers.

2. Odd Numbers
All numbers which can’t be divided by 2 are called odd numbers, e.g. 1, 3, 5, 7, 9, … are called odd numbers.

3. Natural Numbers
The natural flow of numbers starting from 1 are called natural numbers e.g. 1, 2, 3, 4 and so on.

4. Rational Numbers
Any number in the form of p/q, where p and q are integers and q ≠0 and p & q are in lowest terms, is called a rational number. The set of all rational numbers is denoted by Q.
Q = {x:x = p/q; p, q € 1, q ≠0}

Every integer becomes a rational when we write it in the form of p/q. For example 3 = 3/1, - 8 = - 8/1