I know what is 10's complement of a number, but what is signed 10's complement? I could not find an explanation about it. How can one do addition using signed 10's complement?
I'm pretty sure signed 10s complement is just 10s complement except you devote a bit in memory to represent the minus sign. Eg - 4201 is represented as 1 0100 0010 0000 0001 if you are using binary coded decimal, and 4201 is represented as 0 0100 0010 0000 0001. The minus bit simply tells the machine whether it should perform addition or subtraction. Eg:
(negative number1) + (negative number2) = negative (number1 + number2),
(negative number1) + (positive number2) = (number2 - number1)