While it is possible to perform hexadecimal addition in the same way as in bases 2 and 10, that is with sum and carry, the extra mental arithmetic involved may make this impractical.
For example: in hexadecimal F + D is C carry 1. That is 15 + 13 is 28 or 12 and carry 16.
An easier way of carrying out hexadecimal addition is to convert the original numbers to base 2 or 10, carry out the addition and convert the answer back to hexadecimal.
Hexadecimal subtraction can be carried out by converting the hexadecimal number to binary and using binary subtraction.
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