The Detective’s DeskXander Moss
Parcel sender
“My label reads 1113.”
EASY · CASE FILE
The broken check digit
Easy · RAILSIDER PARCEL OFFICE
One parcel label has been mistyped. The office’s small check-digit rule is printed in full, so no specialist coding knowledge is required. The three parcel codes have been transcribed correctly below.
Read the case file below, or open the interactive desk to examine records, keep notes and submit your reasoning. These are the case materials, without the solution.
Your assignment
Inspect, test and record the finding. What does the verified record establish?
- The candidate descriptions and supplied records are verified.
- Use the stated rules and records; no outside knowledge is needed.
People and accounts
Yuna Hart
Parcel sender
“My label reads 2035.”
Wafa Reed
Parcel sender
“My parcel label reads 5217.”
Case records
Read each record on its own terms. A claim made by a person is different from a fact established by an independent record.
LABEL CHECK RULE
Add three digits, check the fourth
Each label has four digits. Add the first three digits; the final digit must be the last digit of that sum. For example, 1 + 2 + 3 = 6, so 1236 passes.
This is a verified source record for this case. Compare its stated facts with the exact question.
PHOTOGRAPH
The postage stamps
Each parcel had enough postage. Postage does not affect the printed code rule.
Each parcel had enough postage. Postage does not affect the printed code rule.
TIME NOTE
The collection time
All parcels were collected in the afternoon.
All parcels were collected in the afternoon.
Questions to resolve
Does each label pass the printed check-digit rule?
- Xander Moss — “My label reads 1113.”
- Yuna Hart — “My label reads 2035.”
- Wafa Reed — “My parcel label reads 5217.”
Use the interactive case desk to select your finding and cite the records that support it. The answer is checked there, and your progress stays in your browser.
Build your finding
Compare the records with each account. Work out what the evidence establishes, then separate that finding from anything it does not prove.