More Practice Subtraction

The number to be subtracted is negated by the usual means (reflect the bits, add one):

0101 1001 →  1010 0111

Then the binary addition algorithm is used:

00100 111         
 0010 0101   =  3710
 1010 0111   = -8910
 —————————     ————
 1100 1100     -5210

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.

Computer scientists and computer engineers are expected to understand the binary addition algorithm. Practice it. Or you can change your major to Art History (and leave the high-paying jobs to the rest of us). Here is another problem: