0 1111 100 0010 1100 0101 0101 1000 0001 (No overflow)
Practice performing this algorithm until you can do it mechanically, like a computer. Detect overflow by looking at the carry-out of the leftmost column. You don't need to convert the representation to decimal.
Add these numbers, represented in eight bits. Determine if overflow occurs.
0110 1100 1001 1111