i've searched few books but couldn't find few simple statements describing decimal adder.concept is still unclear.also,i've got to perform this experiment "dsign & construct the ckt of decimal adder"..can anybody tell 'bout IC(s) required in this?

 

There are probably reasons why there are no IC's for this purpose. Think about it for a moment and see if you can come up with some. I'll give you a hint. If there was an IC that did the job it wouldn't be much of an assignment. Before you can design an adder you need to decide how you will represent decimal operands and how you will represent the result. What ever you decide about representation the result will be a purely combinatorial circuit.

 

Historically - like in the day of ENIAC - adders were decimal in nature. A decimal adder will work the same as a binary, but use BCD instead of straight binary. Things like AND gates, XOR gates, and the like will work as building blocks.