Perform the following addition: 

   0F4A

   420B

   ----

Answer              1 11      1  1

   0F4A → 0000 1111 0100 1010

   420B → 0100 0010 0000 1011

   ----    --------------------

           0101 0001 0101 0101  → 0x5155

Sometimes a hex addition problem is easy enough to do without converting to binary: 
   014A

   4203

   ----

   434D

 
Compute the following sum using 8 bits. Is there overflow? 
   1101 0010

   0110 1101

   ---------

Answer:
0011 1111 
  11

   1101 0010    21010

   0110 1101    10910

   ---------    ---

   0011 1111     6310

The carry bit of 1 indicates overflow. 
 
Compute the following sum using 8 bits: 
   0000 0001

   1111 1111

   ---------

Answer:
  11111 111

   0000 0001     110

   1111 1111   25510

   ---------  -----

   0000 0000    0010

The carry bit of 1 out of the high order column (leftmost) indicates an overflow.