Adding Numbers with Two's Complement Method

Example №2: Adding the $6$-bit numbers $7_{10} = 000111_2$ and $10_{10} = 001010_2$:

   111    <-- carry bits
  000111
+ 001010
  ______
  010001

Adding positive numbers is the same as with sign & magnitude (except that you'd discard any end-around carry if there is such.)

Example №3: Fun Activity: Let's add $-3_{10}$ and $-11_{10}$ in a $8$-bit, $2$'s complement format!
[Hint: First, represent $-3_{10}$ and $-11_{10}$ in a $8$-bit, $2$'s complement format, and then add them.]