Math Crossword

Math Crossword is a cozy math crossword: fill the empty cells of the crossing equations with the numbers from the stock so that every equation holds. Only the digits 1–9 and + − × ÷ are used, and each equation is calculated from left to right (top to bottom). Every stock number can be used only as many times as it appears, so the remaining stock is a clue too.

- Four difficulties (Easy, Medium, Hard, Expert) on boards from 7×7 up to 13×13; Hard and Expert include equations with negative results

- Five rule sets: Classic, Strict Math (× and ÷ first), Operator Guess (the +, −, ×, ÷ cells are blank too), Free Input (no stock, use 1–9 as often as you like) and Mega (15×15 to 21×21 boards). Switch with the chip on the puzzle list; a short rule screen opens the first time you pick one

- Every puzzle is verified by a solver to have a unique solution reachable by logic alone; difficulty reflects the reasoning needed, not the board size

- The equation bar shows the across and down equations through the selected cell, so you always know what to look at

- Undo / redo and hints when you get stuck (3 per puzzle)

- Cell-first or number-first input, switchable from the play screen; mistakes shown in red; game over after 3 mistakes (can be turned off)

- Same-number highlight, lock for correct cells, haptics and more in Settings; pinch to zoom the large boards

- Progress is saved automatically so you can continue any time

- Play History shows cleared counts, average clear time and total play time per difficulty

- Four gentle themes (Cozy, Dark Night, Sakura, Mint), playable in portrait or landscape

- A short "How to play" guide covers the rules and solving tips, available any time from Settings