Decimal Number System


The number system that we use in our day-to-day life is the decimal number system. Decimal number system has base 10 as it uses 10 digits from 0 to 9. In decimal number system, the successive positions to the left of the decimal point represent units, tens, hundreds, thousands and so on.

Each position represents a specific power of the base (10). For example, the decimal number 1234 consists of the digit 4 in the units position, 3 in the tens position, 2 in the hundreds position, and 1 in the thousands position, and its value can be written as

(1×1000)+ (2×100)+ (3×10)+ (4xl)
(1×103)+ (2×102)+ (3×101)+ (4xl00)
1000 + 200 + 30 + 4
1234

As a computer programmer or an IT professional, you should understand the following number systems which are frequently used in computers.

S.N.Number System and Description
1Binary Number SystemBase 2. Digits used : 0, 1
2Octal Number SystemBase 8. Digits used : 0 to 7
3Hexa Decimal Number SystemBase 16. Digits used : 0 to 9, Letters used : A- F