Here is the intro for Illusion Day. Present one illusion at a time showing the kids how they work. Then pass out each one letting the kids try it out and mastering it before doing the next one. 

The kids will want to know how these work. We really don't what causes our bodies and brains to interpret the signals they way they do. Some have to do with persistence of vision in the eye. You can tell the kids they need to become scientists when they grow up and figure them out!

A Fishy Story. What a great little illusion. I have had sixth graders who were just blown away by this!

Bonus Routine: The Compass That Doesn't Point North.

Close up of compass handling.

Floating a Fork and Spoon in the air. Try this for the class and see if they don't go ape over it! 

Here is another video of it.