The BCD addition of 9₁₀and 7₁₀generates code groups of 1001 0111 and a carry to the next higher position. The final step in the problem is to: A) ignore the lowest order code group because 0000 is a valid code group and prefix the carry with three zeros. B) disregard the carry and add 0110 to the lowest order code group. C) add 0110 to the lowest order code group and then prefix the carry with three zeros. D) add 0110 to both code groups to validate the carry from the lowest order code group.

Question

Quizplus · Accepted Answer

In BCD (Binary Coded Decimal) addition, when the sum exceeds 9 (1001 in binary), an adjustment is made by adding 0110 (6 in decimal) to the result. This is because BCD is designed to represent each decimal digit within a byte but binary addition can exceed the BCD range (0000 to 1001 for 0 to 9). The carry from this adjustment must be accounted for in the next higher position, hence the correct step is to add 0110 to the lowest order code group and then prefix the carry with three zeros to maintain proper BCD format.

The BCD Addition of 910 and 710 generates Code Groups

The BCD Addition of 9₁₀and 7₁₀generates Code Groups