Library›Logic & Lateral Puzzles›One card

A LITTLE SOMETHING WORTH KNOWING

A small discovery. Yours to pass on.

Math & LogicOne small ahaLogic subject

This number-placement puzzle uses a 9 × 9 grid; each row, column and 3 × 3 box must contain the digits 1–9 once.

Think it. Then flip it. ahamoraTap to reveal Back to the cue
Math & LogicOne small aha
Your new ahaSudoku

Sudoku: Number puzzle requiring every digit once in each row, column, and box. Source: Sudoku ↗

ahamoraReference ↗

Keep the thread going

One answer is a beginning.

Share a little curiosity, or follow it into the full collection.

Flip the full deck →

More from Logic & Lateral Puzzles

A few more worth knowing.

  1. 09These word puzzles fit answers to clues into intersecting rows and columns of shared letters.RECALL
    Crossword Puzzles

    Crossword puzzles link intersecting answers by shared letters, first widely published in 1913.

    Open this card ↗
  2. 10Moving stacked disks between three pegs without putting a larger disk on a smaller one takes at least 2ⁿ − 1 moves in this puzzle.RECALL
    The Tower of Hanoi

    The Tower of Hanoi takes at least 2ⁿ − 1 moves for n disks. Three disks need 7 moves; four need 15, rather than 14.

    Open this card ↗
  3. 11Characters who always tell the truth or always lie populate this classic family of identity-deduction puzzles.IDENTIFY
    The Knights and Knaves Puzzle

    Knights and knaves puzzles feature characters who always lie or always tell the truth, requiring careful deduction.

    Open this card ↗