Part $1.$

Start your $4-$bit binary adder by using $4$ buttons as the binary inputs and $4$ LEDs to indicate the input bits. Note the $5^{th}$ led is the carry output. $($Co$)$ The buttons toggle the LEDs on and off.

When the first binary number is displayed on the LEDs the Enter$/$Add button is pressed, the LEDs return to $0000$ ready for the next binary number to be entered. The first number is stored.

The second binary number is entered $($same as the first$)$ and the Enter$/$Add button is pressed. The LEDs should now show the result of the addition.

The Enter$/$Add button is pressed a third time and the LEDs are cleared showing $0000.$ Ready to add two new binary numbers.

Part $2.$

Add an LCD.

The top line of the LCD should display the addition in Decimal. $6+5=11$

The bottom line of the LCD should display the addition in Hexadecimal. $6+5=B$