7 Common Cryptarithm Mistakes

Most cryptarithm mistakes come from losing track of constraints rather than difficult arithmetic.

Forgetting that digits are unique

Keep a small used-digit list. Reusing a digit for a different letter can make an impossible branch look valid.

Forgetting a carry

Write every carry explicitly above the next column.

Allowing a leading zero

Mark leading letters before solving so 0 is removed from their candidate sets immediately.

Testing too many guesses

Before trying a value, ask what the column, parity, used digits and carry already rule out.

Solving one column in isolation

A candidate must work with neighboring columns too. Carries connect the equation.

Not recording candidates

Even three tiny candidate digits beside a letter can prevent repeated work.

Skipping the final substitution

Convert every word to a number and verify the arithmetic once at the end.

Educational note: these techniques are practice methods, not medical or cognitive-performance claims.