two players, one board, four in a row wins
Two players share one pair of markers, both starting on 1 on the factor track below (use coins, counters or just write in pencil). Players take turns: move one marker to a new factor, multiply the two factors together, and colour or initial that product's square on the board in your colour. First player to claim four squares in a row — across, down, or diagonally — wins. Use +, −, ×, ÷ scrap paper if you need to check a product.