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A computer takes data from a user and produces result as information. Although the words 'data
and information' are often used interchangeably, but there is an important distinction between the
two words. In the strict sense, data consists of the raw numbers that computers organise to produce
information.
From an early age, we are introduced to the concept of numbers and counting. Toddlers learn at an
early age that they can carry two cookies, one in each hand. Kindergarteners start counting by twos
and fives. Invariably, we use the decimal number system. Our number system is based on 10, most
likely because we have 10 fingers. Let us learn more about the number system.
Number System
A number system is a collection of numbers used to describe various quantities. There are many
number systems in existence. Consider a digital clock. Digital clocks have 24 hours, each hour
composed of 60 minutes. Each minute is in turn composed of 60 seconds. When you learnt to count,
you used the numbers, like 1, 2, 3, etc. Similarly, computers also have their own number system,
known as the binary number system.
The digital computer represents all kinds of data and information like audio, graphics, video,
text and numbers in binary form. The total number of digits used in a number system is called
its base or radix. Therefore, when someone says that they are working with number system of
radix 2, it means base 2, i.e., binary number system. The base is written after the number as
subscript such as (512) . In this example, the number 10 is written as the subscript to express
10
the number in decimal number system.
The numerical digits, we use today, i.e., 1, 2 and 3 are based on the Hindu-Arabic numeral
system.
Different names for the number 0 include zero, nought, naught, nil, zilch and zip.
There are four types of number systems, which are as follows:
1. Decimal number system 2. Binary number system
3. Octal number system 4. Hexadecimal number system
Decimal Number System
The decimal number system is a standard number system for denoting numbers. It consists of ten
digits from 0 to 9. Only these digits can be used to represent numeric value in decimal number system.
Hence, the base of decimal number system is 10. The decimal number system is the most widely used
number system. The value represented by individual digit depends on the weight and position of the
digit.
The position of first digit towards left side of the decimal point is 0. The position of second digit
towards left side of the decimal point is 1. Similarly, the position of first digit towards right side of
decimal point is –1. The position of second digit towards right side of decimal point is –2, and so on.
8 Computer Genius (V2.1)-VII

