While sitting down, lift your right leg off of the ground a little bit. Move your right foot in a circle above the floor. Now try to draw a figure-eight in the air with your left hand! Can you do both of those at the same time?
Hold your hands out in front of you with your index fingers pointing at each other. Move one hand around and around in a circle (away from you, then back towards you). Now try to move the other hand in a circle in the opposite direction! Can you do both of those at the same time?

Carefully punch 3 small holes near the bottom of an empty carton or jug. Fill the carton or jug with water. Now you have 3 separate streams of water.
Pinch the streams of water together!
The tiny water molecules like to hold on to each other, which is called "surface tension." That's why you can sometimes tie knots in water!

Place a coin underneath a piece of paper. Rub a crayon or a pencil over the coin.
Now you have a "brass rubbing" of the coin! What other things can you make "brass rubbings" out of?

Look around your house and find some small tube-shaped objects such as a small plastic cup, a lip balm tube, a small plastic measuring cup (which sometimes comes with liquid medicines), the cap from a marker pen or highlighter, the top of a tube of toothpaste, etc.
Place one on a table or other hard surface. Put your finger on top of the object, then quickly snap your finger down to the table. This causes the object to spin in interesting ways! Sometimes the object will shoot away from you, so make sure that you're not going to hit anyone (or any breakable objects) when you snap your "break dancer"!
Objects which are narrower at one end will sometimes stand up on their narrow end as they spin!

If you have a good-sized mirror, here's how to make a "levitation illusion." Be very careful so that you don't break the mirror! Carefully lean the mirror against something, then have someone put one leg over the mirror and lift that foot off of the ground a little bit. When you look in the mirror, it looks like the person is floating in the air! If the mirror is too big to get your leg over it, then place a small chair behind the mirror and carefully stand on the chair.