Toss the Object
Bring your class to a large space, either a cafeteria, a gym, or outside if the weather permits. Have them spread out and stand in a big circle. Tell them that they will pantomime a game of catch, but that each person must change the ball, or object, into something else before passing it on.
The teacher begins the game. Bend over and pick up an imaginary object. Take your time with this while the students watch. Mold the imaginary object in your hands, and slowly let it take form. The pace you set and the detail you show will set the tone for how the students perform the activity.
For example, show that you are holding a baseball. By moving your hands around the imaginary ball, you show the students the size and shape of your object.
The way you throw the object to the next person (anybody else in the circle) demonstrates to onlookers what is that size and shape object. To pantomime throwing a baseball, you wind up your arm, lift one leg and lean back on the other, then throw as hard as you can across the circle.
The person you throw to must catch what you threw. Hopefully, each participant will demonstrate an understanding of the object that was thrown to them.
Now, its the next guy's turn! Once he has the baseball, he can make it what he wants. As he molds and shapes the object in his hands, it becomes bigger. It stays round but becomes as big as a basketball. Eventually, he is dribbling his basketball. When ready, he bounces it to another child in the circle.