2’s complement (cont’d)

• Example in 4 bits:

  • How do we represent -6?
  • 6 in binary is 0110
  • Invert: 1001
  • Add 1: 1010
  • Note that if we do the same again, we get the original bit stream.
  • Also note that the msb conveniently tells us the sign of the number.

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