**What is Decimal Number
System? **

Decimal number system is the most common example of

positional notational number system and all the arithmetical calculations

undertaken by human being are carried out on the basis of this number system.

In this system, the symbols used are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and the base

is 10. Thus the number

d_{n-1} d_{n-2}…..d_{ 1} d_{0} means d_{n-1} 10^{n-1} + d_{n-2} 10^{n-2} + ……. + d_{1} 10^{1} + d_{0} 10^{0}

and this is an n-digit number. If the number be extended to

the right of the decimal point, then the powers of the base will be negative

starting from -1.

**For example**, the number 3528 has the magnitude

3528 = 3 × 10^{3} + 5 × 10^{2} + 2 × 10^{1} + 8 × 10^{0}

and the number 26.57 has the magnitude

26.57 = 2 × 10 + 6 × 10^{0} + 5 × 10^{-1} + 7 × 10^{-2}