Cheap kid fun - part 2

In the spirit of easy child entertainment (that might have a kernel of educational value somewhere) here is another activity for you.

Take some white vinegar.  Add a few drops of food colouring to it.

Then, take a box of baking soda and spread it out on a baking sheet.

Not too complicated yet, right?

Okay, add a few kids and a few spoons/eye droppers and set them loose.

There was much fizzing and oohing and ahhing and relatively little mess at the end!  Doesn't get easier than that and prepares the kiddos for the inevitable volcano-science-project in their future.