Emulator of binary adder

1. Set number of bits e.g. 4 to get 4-bit adder
2. Add first number in binary e.g. 1 {enter}; 0 {enter}; 0 {enter}; 0 {enter}; to get 1 in decimal
3. Add second number in binary e.g. 1 {enter}; 0 {enter}; 0 {enter}; 0 {enter}; to get 1 in decimal
4. You get your result e.g. 1000 + 1000 = 0100 which can be interpret as $0\times 2 ^ 0 + 1\times 2 ^ 1 + 0\times 2 ^ 2 + 0\times 2 ^ 3 = 2$