No! Not More Practice Subtraction!

The number to be subtracted is negated by the usual means, as in the previous problem. Then the "binary addition algorithm" is used:

11100 111       
 1110 0101   = -2710
 1010 0111   = -8910
 ---------    -----
 1000 1100    -11610

Since the carry into the most significant column is the same as the carry out of that column the result is correct. The answer came out negative, but that is fine.

A computer does several million of these operations per second. Surely you can do another one? How about if I give you two whole seconds?