Oobleck

Who needs toys when you've got fun right in your own kitchen?

1 cup corn starch
1/2 cup water
food coloring (optional)

(The amount of corn starch and water can vary as long as you keep the ratio the same.)

Stir.  Mix.  Play.  Learn.

While you're playing, how about throwing a little science lesson their way?  (They'll never know what hit them.)

Talk with your kids about the three states of matter: solid, liquid and gas.

Now talk about the fourth state of matter known as a suspension.

When you squeeze the cornstarch and water mixture it feels like a solid because all of the molecules line up.....

The molecules relax and act like a liquid when nothing is pressing on them....

Now go learn, and have fun while you're doing it!