Hands on coordinate planes. Fun. Students toss two dice, form a coordinate pair and place a marker on that intersection. Students alternate turns, each trying to be the first to get four markers in a row horizontally, vertically or diagonally.
Battleship in math class. Taking it in a slightly more advanced direction, lets make a 4 quadrant Battleship grid. And lets require kids to write equations in slope-intercept form, graph them, and develop a strategy for this process. (Putting equations in point-slope would be a great substitute if you want one.) P1