Styrofoam balls

Today in class we were using styrofoam balls and the overhead projector to recreate the phases of the moon.  I had the boys go first since there weren’t enough balls for everyone to go at the same time.  I’m very careful when discussing this demo to avoid referring to the props in the plural form.  Here were a few of the choice comments:

Student:  Hey, tell him to move.  His head is blocking our balls.

Me: It’s time to switch and give the girls a turn.

Other student:  Should we give the girls our balls?

(Must keep straight face.  Must keep straight face.)