Puzzles
An addition puzzle where letters stand for digits, and there's only one right answer
SEND + MORE = MONEY. Each letter represents a different digit 0–9 (no leading zeros), and the addition has to work exactly as written. Find the digits.
Reveal the answer
9567 + 1085 = 10652, meaning S=9, E=5, N=6, D=7, M=1, O=0, R=8, Y=2. Henry Dudeney invented this 'cryptarithm' — arithmetic disguised as a word puzzle — for The Strand Magazine in July 1924. It remains the genre's most famous example, still used to teach constraint-satisfaction search in computer science courses.