Hex addition follows the same column method as decimal, but each column holds values up to 15 and carries at 16.
For each column, from the right:
- Turn the digits into their values (A = 10, …, F = 15) and add them, plus any carry.
- If the total is 15 or less, write it as one hexadecimal digit (10–15 become A–F). No carry.
- If it's 16 or more, subtract 16, write that digit, and carry 1.
A column total is at most 15 + 15 + 1 = 31, so the carry is never more than 1.
The most common slip is carrying at 10 out of habit. 9 + 7 = 16 = 10₁₆, but 9 + 6 = 15 = F, with no carry.
If you prefer, you can always convert both numbers to binary, use binary addition, and convert back. Hex is just a shorthand for the same bits.
8
16¹
A
16⁰