Page 24 - Computer Class 06

Number System

Number systems are the technique to represent numbers in the computer system
architecture, every value that you are saving or getting into / from computer memory
has a defined number system. Generally, we use a number system in which there are

10 different symbols 0, 1, 2, 3, - - - - - -9. This number system is known as decimal
number system. But computer does not understand decimal number system. It
understands a number system that uses only two symbols 0 and 1 where 0 means
“off” and 1 means “on” state in binary number system and is called binary number
system.

In addition to these two, there are some more number systems such as octal number
system and hexadecimal number system.

The value of each digit in a number can be determined using :
8 the digit.

8 the position of the digit in the number.

8 the base of the number system (where the base is defined as the total number of
digits available in the number system).

Let’s study the following chart to understand various number systems.

S. No Number System Base Digits/Letters Used

1. Decimal Number System 10 0 to 9

2. Binary Number System 2 0 and 1

3. Octal Number System 8 0 to 7

4. Hexadecimal Number 16 Digits 0 to 9 and letters

System A to F

1. Decimal Number System : The number system that we use in our day-to-day life is
the decimal number system. As it uses total 10 digits from 0 to 9 it has base 10.
2. Binary Number System : A binary number system has only two digits that are 0

and 1. Every number (value) represents with 0 and 1 in this number system. The
base of binary system is 2, because it has only two digits.

3. Octal Number System : Octal number system is a number system that has 8
different symbols namely 0, 1, 2, 3, - - - - - - 7. It is also called as base 8
number system.

Computer-6 24 Computer-1