The Boat and the Shark: This activity works well for 3-5 graders. It is an activity which helps teach the concept about positive and negative integers. This is a great activity to get the students working together and enjoying themselves. By clicking on the following attachment, you can view the worksheet which presents the object of the game, tools needed, and how to play the game. I will definately use this in my future classroom.

Image: http://www.noeticart.com/clipart/shark.jpg