Q. Illustrate Decimal Fixed Point Representation?

The point of this representation is to keep the number in decimal equivalent form and not binary as above. A decimal digit is signified as a combination of four bits so a four digit decimal number will need 16 bits for decimal digits representation and extra 1 bit for sign. Generally to keep convention of one decimal digit to 4 bits the sign sometimes is assigned a 4-bit code too. This code can be bit combination that hasn't been used to signify decimal digit for example 1100 can represent plus whereas 1101 can represent minus. 

For illustration a simple decimal number - 2156 can be signified as:

Though this technique wastes substantial amount of storage space however it doesn't need conversion of a decimal number to binary. So it can be used at places where amount of computer arithmetic is less than of the amount of input/output of data for example calculators or business data processing situations. The arithmetic in decimal can be performed as in binary too except that in place of signed complement signed nine's complement is used and in place of signed 2's complement signed 9's complement is used.