3. Adding Unsigned Numbers

1. Let's first solve the problem for addition of one-bit quntities:

        0 + 0 =  0
        0 + 1 =  1
        1 + 0 =  1
        1 + 1 = 10
   

   • The last line indicates that we have a carry output.

   • That is, one-bit quantity cannot accommodate (1 + 1).

   • Therefore, larger data type is required for (1 + 1) to succeed.

2. When multi-bit unsigned quantities are added, overflow occurrs if there is a carry out from the leftmost (most significant) bit.