Which statement accurately describes the final verification step for a manually checked DEA number?

Which statement accurately describes the final verification step for a manually checked DEA number?

• A. Compare the last digit of the total from step 3 to the last digit of the DEA number.
• B. Multiply the total by 2 and compare to the last digit.
• C. Add only the odd-position digits and compare to the first digit.
• D. Subtract step 2 result from step 1 and compare to the penultimate digit.

Answer: (A)

DEA numbers include a check digit to catch input errors, so the final step is about confirming that the computed check matches the actual check digit in the number. After summing the digits in odd positions (doubling that sum) and adding the digits in even positions, you get a total. The last digit of that total should equal the last digit of the DEA number—the check digit. If they match, the number passes the manual verification; if not, it indicates an error in entry. This is why stating that the final verification step is to compare the last digit of the total from the calculation to the last digit of the DEA number is correct. The other options describe steps that aren’t part of the check-digit method, such as multiplying the total again, comparing to the first digit, or subtracting intermediate results to get a different position’s digit.

DEA numbers include a check digit to catch input errors, so the final step is about confirming that the computed check matches the actual check digit in the number. After summing the digits in odd positions (doubling that sum) and adding the digits in even positions, you get a total. The last digit of that total should equal the last digit of the DEA number—the check digit. If they match, the number passes the manual verification; if not, it indicates an error in entry.

This is why stating that the final verification step is to compare the last digit of the total from the calculation to the last digit of the DEA number is correct. The other options describe steps that aren’t part of the check-digit method, such as multiplying the total again, comparing to the first digit, or subtracting intermediate results to get a different position’s digit.