Assalamo Allykum !
You can do easily using the MULTISIM .
For the input you can use switches. These switches are on off by a particular key of the keyboard. (e.g. "a" for one switch, "b" for second switch, and so on)
For the display of the sum you can use the 7-segment display on the output. In the MULTISIM there is 4-bit 7-Segment display. there is no need for the 7-Segment displa decoder. This is automatically convert the bit to the 7-Segment dsplay.
And for the output of carry you can use the simple LED, I trhink thta is very easy.
Wish you a good luck.
Take Care.