YAOKU

ADD. MULTIPLY. CONNECT.

How to play YAOKU

YAOKU is a number-placement logic puzzle built around sum clues, product badges, and a shared set of Loose Cards. Fill every white square so all the clues work together. White squares use digits 1–9.

Play a Free Play puzzle → Explore the numbered collection

The one-minute quick start

  1. Tap an empty white square, then tap a Loose Card. Its digit fills the square. Fixed numbers are already given and cannot be changed.
  2. Arrows mean add. The white squares along an arrow must add up to its clue. Stop at the next gray square or the edge. Do not repeat a digit within that group.
  3. Small square badges mean multiply. The two white squares beside a badge multiply to its number. Read the tens above-left and the ones below-right: a 3 and a 0 mean 30, so 5 × 6 is one possible pair.
  4. Use every Loose Card once. Matching cards are separate copies. Fixed numbers do not use cards. The cards are shuffled; their order gives no hints.

A worked clue example

An across sum of 12 could be filled by 3, 4, and 5: 3 + 4 + 5 = 12, with no repeats. A product badge of 06 means 6, not zero: its neighbors could be 1 and 6, or 2 and 3. These are clue examples, not the solution to every puzzle; crossing clues and your available cards determine which digits fit.

Helpful tools and keyboard controls

Undo and Erase let you change your mind. Notes add pencil marks without using cards. Check identifies entries that do not match the puzzle’s solution; Hint can reveal a connection. You can pause the timer or restart the same puzzle.

Use digits 1–9 to enter a number, arrow keys to move, Backspace or Delete to erase, N for notes, and Ctrl/⌘ Z to undo. On a phone, tap a square and then a Loose Card.

What makes the rules different?

There are no Sudoku boxes. A digit cannot repeat within one sum group, but it may appear in other groups. Each badge connects only its two neighboring white squares. Zero can appear in a badge’s displayed number, not in a white square.

Collection or Free Play?

The Collection contains 1,000 numbered puzzles with fixed identities. Free Play generates a new puzzle in your browser. Easy, Medium, and Hard ratings are provisional estimates. Your entries, notes, and progress are saved in this browser on this device, not synchronized between devices.

Sharing a puzzle gives someone the same starting clues, not your entries or notes. For a new Free Play puzzle, opening Share starts saving its definition to create a public link. See the Privacy Policy for details.

YAOKU is for people age 13 and older. Start playing, or open the playable collection.