棋盘中仅有一个残缺方块。将棋盘分成四个大小相等的小棋盘，则残缺方块必在其中一个小棋盘中。此时用三格板覆盖在其他三个小棋盘的交界处，刚好使这三个小棋盘均有一个方块被覆盖。

-Board, only a crippled box. The board is divided into four equal-sized small board, which is incomplete will be a small box in the board. This time with three other grid plate covering the junction of three small board, just so that the three have a small board box is covered.