CALL + THEIR = OFFICE
What is this puzzle?
Solve the addition alphametic puzzle where CALL + THEIR = OFFICE. Each letter represents a unique digit from 0-9. No number starts with zero.
Difficulty: hard · Category: addition · Unique letters: 10
This hard-level addition alphametic puzzle features 10 unique letters (A, C, E, F, H, I, L, O, R, T). In the equation CALL + THEIR = OFFICE, each letter maps to a distinct digit from 0 to 9. The leading letters C and T and O cannot represent zero — this is your first constraint. The result "OFFICE" has more digits than any addend, which means there must be a carry into the leftmost position. This is a crucial clue for determining the result's leading letter. This is a challenging puzzle that requires systematic use of carry analysis, parity checking, and elimination. Start by listing all constraints, then methodically eliminate impossible digit assignments.
- This addition alphametic has 10 unique letters to determine.
- Leading letters: C, T, O. None of these can be zero.
- All 10 digits (0–9) are used, one per letter.
- Start from the rightmost column (units place) and work left, tracking carries between columns.
- With two addends, each column can produce a carry of at most 1.
- With many unique letters, use elimination and constraint tracking to narrow down possibilities step by step.