### A good answer might be:

256

256

Every pattern of the 256 patterns has been assigned an integer to represent.

# The "Sign Bit"

The algorithm that creates the repn of the negative an integer works with both positive and negative integers. Start with `N` and complement it (make its negative): you get `-N`. Now complement `-N` and you get the original `N`.

>     0110 1101     →  1001 0010     add one →  1001 0011

>     1001 0011     reflect →  0110 1100     add one →  0110 1101

With N-bit two's comp repn, the high order bit is "0" for positive integers and "1" for negative integers. This is a fortunate result. The high order bit is sometimes called the sign bit. But it is not really a sign (it does not play a separate role from the other bits). It takes part in the "binary addition algorithm" just as any bit.

### QUESTION 21:

Does the following four-bit two's complement represent a negative or a positive integer?

     1001