It is also known as XS-3. We add 310 or 1102 to the each 4-bit combination of BCD codes to get excess-3 codes. We can see the corresponding Excess-3 codes of each BCD number: Decimal Binary BCD Excess-3 0 0000 0000 0011 0001 0001 0100 0010 0010 0101 0011 0011 0110 0100 0100 0111 0101 […]
