ref: 322a439d801c91cf30a208cff499b33f4a5a2123
dir: /html/sixteen.html/
Sixteen <p> Slide the grid squares around so that the numbers end up in consecutive order from the top left corner. <p> Click on the arrows at the edges of the grid to move a row or column left, right, up or down. The square that falls off the end of the row comes back on the other end.