Mark the location of the teams your home team plays on a map!
Also, check out The Physics of Baseball article over at CNet. Paul Doherty from Exploratorium demonstrated the experiments mentioned above! (Photo Credit: James Martin/CNET Networks)
Angles - Finding the perfect swing! The angle you swing the bat determines the ball's distance and height! Also, try throwing the ball at different angles. What angle is the ideal pitch? Click here for details.
Learn Your Shapes: sphere (ball), diamond (field), square (bases), pentagon (home plate), circle (pitcher's mound)
Find the perimeter / area of a base and the circumference of the pitcher's mound!
Practice telling time, record the duration of baseball practice or a game! Click here for details!