I designed and built a circuit that adds 2 two-bit numbers and represents the sum in binary via LEDs. This circuit may be simplified by using the 4 bit adder IC (7483). To increase the number of bits being added, the final carry out can become an input for the next full adder. This process may be repeated to achieve the number of bits needed.

Parts used: 2 input XOR Gate (7486), 2 input NAND Gate (7400), HEX Inverter (7404), 2 input NOR Gate (7402), 3 LEDs, 5V Power Supply.