Addition & Subtraction
Just like in grade school (carry/borrow 1s) 0111 0111 0110 + 0110 - 0110 - 0101
Two's complement operations easy
- subtraction using addition of negative numbers 0111 + 1010
Overflow (result too large for finite computer word):
- e.g., adding two n-bit numbers does not yield an n-bit number 0111 + 0001 note that overflow term is somewhat misleading, 1000 it does not mean a carry “overflowed”