**Introduction to Computer****Generation of Computer****Types of Computer****Component of Computer****Central Processing Unit****Input devices****Output devices****Computer Memory****Computer Ports****Computer Software****Programming Language****Flow Chart****Number System**- » Kinds of Number Systems
- » Converting Decimal Integer to Binary, Octal, Hexadecimal
- » Converting Decimal Fraction to Binary, Octal, Hexadecimal
- » Converting Decimal Integer Fraction to Binary, Octal, Hexadecimal
- » Conversion of Binary, Octal, Hexadecimal to Decimal
- » Conversion of Binary to Octal, Hexadecimal
- » Conversion of Octal, Hexadecimal to Binary
- » Binary Arithmetic
- » Complement of Binary Numbers
- » Binary Data Representation
- » Binary Coding Schemes
**Operation System****DOS OS & Commands****Computer Network****Internet****MCQ on FOC**

## Number System

A number system in base r or radix r uses unique symbols for r digits. One or more digits are combined to get a number. The base of the number decides the valid digits that are used to make a number. In a number, the position of digit starts from the right-hand side of the number. The rightmost digit has position 0, the next digit on its left has position 1, and so on. The digits of a number have two kinds of values—

• Face value

• Position value

## Face Value

The face value of a digit is the digit located at that position. For example, in decimal number 52, face value at position 0 is 2 and face value at position 1 is 5.

## Position Value

The position value of a digit is (base ^{position}).

**Example :** In decimal number 52, the position
value of digit 2 is 100 and the position value of digit 5 is 10^{1}. Decimal numbers have a base of 10.

The number is calculated as the sum of, face value * base^{position}, of each of the digits. For
decimal number 52, the number is 5*10^{1} + 2*10^{0} = 50 + 2 = 52.

**In computers, we are concerned with four kinds of number systems, as follows —**

• Decimal Number System — Base 10

• Binary Number System — Base 2

• Octal Number System — Base 8

• Hexadecimal Number System — Base 16

The numbers given as input to computer and the numbers given as output from the computer, are generally in decimal number system, and are most easily understood by humans. However, computer understands the binary number system, i.e., numbers in terms of 0s and 1s. The binary data is also represented, internally, as octal numbers and hexadecimal numbers due to their ease of use.