Decimal number system characteristic is the linear array of digits and also their significant placing.For example number 4324 can be represented :
4324 = 4×1000 + 3×100 + 2×10 + 4×1
Number 4 on the left is of differing significance to that of number 4 on the right.
The fundamental of the decimal number system is the availability of 10 different digits.They permit counting from 0 to 9. If counting is to excees the number 9, this constitutes acarry over to the next place digit.The significance of this place is 10, and the next carry over takes place when 99 is reached.