0011 1111 

  11
   1101 0010    21010
   0110 1101    10910 
   0011 1111     6310

Yet More Addition Practice

The correct application of the Binary Addition Algorithm sometimes gives incorrect results (because of overflow).

With paper-and-pencil arithmetic, overflow is not a problem because you can use as many columns as needed.

Correct Unsigned Binary Addition
When the Binary Addition Algorithm is used with unsigned binary integer representation: The result is CORRECT only if the CARRY OUT of the high order column is ZERO.

But digital computers use fixed bit-lengths for integers, so overflow is possible. For instance some processors represent integers in 8, 16, or 32 bits. When 8-bit operands are added, overflow is certainly possible. Our MIPS processor uses 32-bit integers, but even then, overflow is possible.

For interesting videos showing the consequences of overflow, google Ariane flight V88.

   0000 0001
   1111 1111